Information Notice 1997-38, Level-Sensing System Initiates Common-Mode Faulure of High-Pressure-Injection Pumps: Difference between revisions

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{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555-0001June 24, 1997NRC INFORMATION NOTICE 97-38: LEVEL-SENSING SYSTEM INITIATES COMMON-MODE FAILURE OF HIGH-PRESSURE-INJECTIONPUMPS
{{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY
 
COMMISSION
 
===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C. 20555-0001 June 24, 1997 NRC INFORMATION
 
NOTICE 97-38: LEVEL-SENSING
 
SYSTEM INITIATES
 
COMMON-MODE FAILURE OF HIGH-PRESSURE-INJECTION
 
PUMPS


==Addressees==
==Addressees==
All holders of operating licenses or construction permits for nuclear power reactors.
All holders of operating
 
licenses or construction
 
permits for nuclear power reactors.


==Purpose==
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alertaddressees to a recent incident in which two high-pressure-injection (HPI) pumps weredamaged as a result of an inaccurate letdown storage tank (LDST) level-sensing system.The inaccuracy was caused by a drained reference leg. As a result, an incorrect level wasdisplayed, permitting the pumps to take suction from an empty tank. It is expected thatrecipients will review this information for applicability to their facilities and consider actions, asappropriate. However, suggestions contained in this information notice are not NRCrequirements; therefore, no specific action or written response is required.Descdrition of CircumstancesOn May 3, 1997, the licensee for Oconee Unit 3 was conducting a planned shutdown toinspect an HPI line. During cooldown of the plant, HPI pump 3B was operating in the reactorcoolant system (RCS) makeup mode. The pump's discharge pressure dropped to the "low'pressure setpoint initiating the automatic start of standby HPI pump 3A. The operators latersecured pump 3A when reactor coolant pump (RCP) seal injection flow indicated "high". TheHPI header pressure decreased again. HPI pump 3A automatically restarted. The pump'smotor current began oscillating. The operators secured HPI pump 3B because of anindication of low motor current. Shortly afterwards, HPI pump 3A was also secured when itsmotor current decreased sharply. The licensee issued a Notification of an Unusual Eventbecause of the loss of two of the three HPI pumps.The licensee later concluded that both HPI pumps became hydrogen bound and possiblydamaged when they took suction from an empty LDST even though adequate tank inventorywas indicated.De4e NOrTLdE 1-0o3' 970o6 4U(WH)oLA .B~O~ 31O1lMa c rz I -rePUndi aqquafac @)  
The U.S. Nuclear Regulatory
IN 97-38June 24, 1997 DiscussionThe HPI pumps at Oconee perform the dual functions of RCS makeup and high-pressuresafety injection. These pumps normally take suction from the LDST (also referred to as themakeup or volume control tank by other vendors). A 25-psi (172.4 kPa) hydrogenoverpressure is maintained in this tank to scavenge oxygen from the RCS.During this event, two level transmitters monitored tank level. These transmitters producelevel alarms in the control room. The alarms alert operators to initiate makeup to the LDST.Both level transmitters shared a common reference leg. Because the shared reference legwas partially drained, the indicated letdown tank level remained at 9 inches above thelow-level alarm setpoint. The tank was actually empty, its contents having been depletedduring normal charging. Letdown tank level was investigated only after both HPI pumpsdeveloped problems.Indicated level in the control room was derived from the equivalent pressure differencebetween the drained reference leg and the back pressure from the 25 psi hydrogenoverpressure in the LDST. Because both level instruments shared the common referenceleg, both gave the same erroneous indication. Therefore, operators failed to provide makeupinventory to the LDST. Two of the three HPI pumps became gas-bound, cavitated, and, as aresult, were structurally damaged.If an actual safety injection actuation occurs, the suction isolation valve to the LDST remainsopen while the suction isolation valve to the borated water storage tank (BWST) opens on thesafety injection signal. All three HPI pumps receive a start signal and take suction on boththe LDST and the BWST. With the two tanks cross-tied, the potential existed for this event tohave caused the loss of all HPI pumps as a result of gas binding. Loss of all three HPIpumps could prevent the successful mitigation of a loss of coolant accident. During normaloperations, loss of all HPI pumps would result in the loss of reactor coolant pump sealinjection, normal RCS makeup, and normal boration.The level transmitters were last calibrated in February 1997. Sometime between that lastcalibration and the event, a leak developed from a scored cap on a test connection thatdrained the reference leg. The cap was used to isolate the test connection. A drainedreference leg or a reference leg with entrained air can result in incorrect level indication.Incorrect level indication will prevent appropriate setpoints being reached when processconditions demand, defeat critical automatic safety functions, and could mislead plantoperators into taking less than conservative actions.Pressure and level sensors, in any safety-related application, that rely on a reference leg fora differential pressure reading, are sensitive to changes in reference leg level. Normalsurveillances that Include only channel checks with other instruments sharing the referenceleg or transmitter calibrations with external hydrostatic test sets will not reveal the truecondition of the reference leg. In the absence of an automatic reference leg fill system,periodic verification of reference leg level based on the plant-specific environment is neededto ensure the operational integrity of the critical systems that are relied upon for manual andautomatic functions.
 
Commission (NRC) is issuing this information
 
notice to alert addressees
 
to a recent incident in which two high-pressure-injection (HPI) pumps were damaged as a result of an inaccurate
 
letdown storage tank (LDST) level-sensing
 
system.The inaccuracy
 
was caused by a drained reference
 
leg. As a result, an incorrect
 
level was displayed, permitting
 
the pumps to take suction from an empty tank. It is expected that recipients
 
will review this information
 
for applicability
 
to their facilities
 
and consider actions, as appropriate.
 
However, suggestions
 
contained
 
in this information
 
notice are not NRC requirements;  
therefore, no specific action or written response is required.Descdrition
 
of Circumstances
 
On May 3, 1997, the licensee for Oconee Unit 3 was conducting
 
a planned shutdown to inspect an HPI line. During cooldown of the plant, HPI pump 3B was operating
 
in the reactor coolant system (RCS) makeup mode. The pump's discharge
 
pressure dropped to the "low'pressure setpoint initiating
 
the automatic
 
start of standby HPI pump 3A. The operators
 
later secured pump 3A when reactor coolant pump (RCP) seal injection
 
flow indicated "high". The HPI header pressure decreased
 
again. HPI pump 3A automatically
 
restarted.
 
The pump's motor current began oscillating.
 
The operators
 
secured HPI pump 3B because of an indication
 
of low motor current. Shortly afterwards, HPI pump 3A was also secured when its motor current decreased
 
sharply. The licensee issued a Notification
 
of an Unusual Event because of the loss of two of the three HPI pumps.The licensee later concluded
 
that both HPI pumps became hydrogen bound and possibly damaged when they took suction from an empty LDST even though adequate tank inventory was indicated.
 
De4e NOrTLdE 1-0o3' 970o6 4 U(WH)oLA .B~O~ 31O1 lMa c rz I -reP Undi aqquafac @)  
IN 97-38 June 24, 1997 Discussion
 
The HPI pumps at Oconee perform the dual functions
 
of RCS makeup and high-pressure
 
safety injection.
 
These pumps normally take suction from the LDST (also referred to as the makeup or volume control tank by other vendors).
 
A 25-psi (172.4 kPa) hydrogen overpressure
 
is maintained
 
in this tank to scavenge oxygen from the RCS.During this event, two level transmitters
 
monitored
 
tank level. These transmitters
 
produce level alarms in the control room. The alarms alert operators
 
to initiate makeup to the LDST.Both level transmitters
 
shared a common reference
 
leg. Because the shared reference
 
leg was partially
 
drained, the indicated
 
letdown tank level remained at 9 inches above the low-level
 
alarm setpoint.
 
The tank was actually empty, its contents having been depleted during normal charging.
 
Letdown tank level was investigated
 
only after both HPI pumps developed
 
problems.Indicated
 
level in the control room was derived from the equivalent
 
pressure difference
 
between the drained reference
 
leg and the back pressure from the 25 psi hydrogen overpressure
 
in the LDST. Because both level instruments
 
shared the common reference leg, both gave the same erroneous
 
indication.
 
Therefore, operators
 
failed to provide makeup inventory
 
to the LDST. Two of the three HPI pumps became gas-bound, cavitated, and, as a result, were structurally
 
damaged.If an actual safety injection
 
actuation
 
occurs, the suction isolation
 
valve to the LDST remains open while the suction isolation
 
valve to the borated water storage tank (BWST) opens on the safety injection
 
signal. All three HPI pumps receive a start signal and take suction on both the LDST and the BWST. With the two tanks cross-tied, the potential
 
existed for this event to have caused the loss of all HPI pumps as a result of gas binding. Loss of all three HPI pumps could prevent the successful
 
mitigation
 
of a loss of coolant accident.
 
During normal operations, loss of all HPI pumps would result in the loss of reactor coolant pump seal injection, normal RCS makeup, and normal boration.The level transmitters
 
were last calibrated
 
in February 1997. Sometime between that last calibration
 
and the event, a leak developed
 
from a scored cap on a test connection
 
that drained the reference
 
leg. The cap was used to isolate the test connection.
 
A drained reference
 
leg or a reference
 
leg with entrained
 
air can result in incorrect
 
level indication.
 
Incorrect
 
level indication
 
will prevent appropriate
 
setpoints
 
being reached when process conditions
 
demand, defeat critical automatic
 
safety functions, and could mislead plant operators
 
into taking less than conservative
 
actions.Pressure and level sensors, in any safety-related
 
application, that rely on a reference
 
leg for a differential
 
pressure reading, are sensitive
 
to changes in reference
 
leg level. Normal surveillances
 
that Include only channel checks with other instruments
 
sharing the reference leg or transmitter
 
calibrations
 
with external hydrostatic
 
test sets will not reveal the true condition
 
of the reference
 
leg. In the absence of an automatic
 
reference
 
leg fill system, periodic verification
 
of reference
 
leg level based on the plant-specific
 
environment
 
is needed to ensure the operational
 
integrity
 
of the critical systems that are relied upon for manual and automatic
 
functions.
 
IN 97-38 June 24, 1997 This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about information
 
in this notice, please contact one of the technical
 
contacts listed below or the appropriate
 
Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts:
Thomas Koshy, NRR 301-415-1176 E-mail: txkenrc.gov
 
Nick Fields, NRR 301-415-1173 E-mail: enfenrc.gov
 
Attachment:
List of Recently Issue Information
 
Notices 4' ln.44
 
===I Attachment===
IN 97-38.June 24, 1997 LIST OF RECENTLY ISSUED NRC INFORMATION
 
NOTICES Information
 
Date of Notice No. Subject Issuance Issued to 96-53, Supp. 1 97-37 Retrofit to Amersham 660 Posilock Radiography
 
Camera to Correct Incon-sistency in 10 CFR Part 34 Compatibility
 
Main Transformer
 
Fault with Ensuing Oil Spill into Turbine Building 06/23/97 06/20/97 All industrial
 
radiography
 
licensees All holders of OLs or CPs for nuclear power reactors 97-36 97-35 97-34 Unplanned
 
===Intakes by Worker of Transuranic===
Airborne Radioactive
 
Materials
 
and External Exposure Due to Inadequate
 
===Control of Work Retrofit to Industrial===
Nuclear Company (INC)IR100 Radiography
 
===Camera to Correct Inconsistency===
in 10 CFR Part 34 Compatibility
 
Deficiencies
 
in Licensee Submittals
 
Regarding Terminology
 
for Radio-logical Emergency
 
===Action Levels in Accordance===
With the New Part 20 06/20/97 06/18/97 06/12/97 All holders of OLs and CPs permits. All licensees
 
of of nuclear power reactors in the decommissioning
 
stage and fuel cycle All industrial
 
radiography
 
licensees All holders of OLs or CPs for test and research reactors OL = Operating
 
License CP = Construction
 
Permit
 
I KU IN 97-38 June 24, 1997 This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about information
 
in this notice, please contact one of the technical
 
contacts listed below or the appropriate
 
Office of Nuclear Reactor Regulation (NRR) project manager.original signed by S.H. Weiss for Marylee M. Slosson, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts: Thomas Koshy, NRR 301-415-1176 E-mail: txk@nrc.gov
 
Nick Fields, NRR 301-415-1173 E-mail: enf@nrc.gov
 
Attachment:
List of Recently Issued NRC Information
 
Notices Tech Editor has reviewed and concurred
 
on 5/14197 DOCUMENT NAME: G:XNICKIOCONEE.IN
 
*SEE PREVIOUS CONCURRENCES
 
To receive a co of this document.
 
indicate In the box C=Coov wlo attachmentlendosure
 
E=Coov with attachment/endosure
 
N = No coy OFFICE Tech x HICB* x PECB* DRPM Contacts*NAME NFields JWermiel AChaffee MSlosson 5___ __ __ TK oshy _ _ _ _ _ _ _ _ _ _DATE 06/09/97 06/09/97 06/12/97 V07 OFFICIAL KRCORU COPY-
I S .--4 K-IN 97-xx June xx, 1997 This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about information
 
in this notice, please contact one of the technical
 
contacts listed below or the appropriate
 
Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
contacts:
Thomas Koshy, NRR 301-415-1176 E-mail: txk@nrc.gov
 
Nick Fields, NRR 301-415-1173 E-mail: enfenrc.gov
 
Attachment:
List of Recently Issued NRC Information
 
Notices DOCUMENT NAME: G:%NICKkOCONEE.IN
 
*SEE PREVIOUS CONCURRENCES
 
To receive a conv of this document indicate in the box C=Coov wlo attachmentlenclosure
 
E=Coov with attachmentlenclosure
 
N = No copy OFFICE Tech x HICB* l x PECB* DRPM Contacts*
ll NAME NFields JWermiel AChaffee MSlosson TKoshy DATE 06/09/97 06/09/97 06112/97 4/ /97 OFFICIAL RECORD COPY~ 6171k
 
; I K'J IN 97-xx June xx, 1997 This information
 
notice requires no specific action or written response.
 
If you have any questions
 
about information
 
in this notice, please contact on6 of the technical
 
contacts listed below or the appropriate
 
Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting Director Division of Reactor Program Management
 
===Office of Nuclear Reactor Regulation===
Technical
 
Contacts: Thomas Koshy, NRR 301-415-1176 e-mail:txk@nrc.gov
 
Nick Fields, NRR 301-415-1173 e-mail:enfenrc.gov
 
Attachment:
List of Recently Issued NRC Information
 
Notices DOCUMENT NAME: G:\NICK\OCONEE.IN


IN 97-38June 24, 1997 This information notice requires no specific action or written response. If you have anyquestions about information in this notice, please contact one of the technical contacts listedbelow or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts: Thomas Koshy, NRR301-415-1176E-mail: txkenrc.govNick Fields, NRR301-415-1173E-mail: enfenrc.govAttachment: List of Recently Issue Information Notices4' ln.44 IAttachmentIN 97-38.June 24, 1997 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-53,Supp. 197-37Retrofit to Amersham 660Posilock RadiographyCamera to Correct Incon-sistency in 10 CFR Part 34CompatibilityMain Transformer Faultwith Ensuing Oil Spillinto Turbine Building06/23/9706/20/97All industrial radiographylicenseesAll holders of OLs or CPsfor nuclear power reactors97-3697-3597-34Unplanned Intakes byWorker of TransuranicAirborne RadioactiveMaterials and ExternalExposure Due to InadequateControl of WorkRetrofit to IndustrialNuclear Company (INC)IR100 Radiography Camerato Correct Inconsistencyin 10 CFR Part 34CompatibilityDeficiencies in LicenseeSubmittals RegardingTerminology for Radio-logical Emergency ActionLevels in AccordanceWith the New Part 2006/20/9706/18/9706/12/97All holders of OLs and CPspermits. All licensees ofof nuclear power reactorsin the decommissioningstage and fuel cycleAll industrial radiographylicenseesAll holders of OLs or CPsfor test and researchreactorsOL = Operating LicenseCP = Construction Permit
To receive a copy of tis document, indicate in the box C=Copy wlo attachment/enclosure


IKUIN 97-38June 24, 1997 This information notice requires no specific action or written response. If you have anyquestions about information in this notice, please contact one of the technical contacts listedbelow or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.original signed by S.H. Weiss forMarylee M. Slosson, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Thomas Koshy, NRR301-415-1176E-mail: txk@nrc.govNick Fields, NRR301-415-1173E-mail: enf@nrc.govAttachment: List of Recently Issued NRC Information NoticesTech Editor has reviewed and concurred on 5/14197DOCUMENT NAME: G:XNICKIOCONEE.IN *SEE PREVIOUS CONCURRENCESTo receive a co of this document. indicate In the box C=Coov wlo attachmentlendosure E=Coov with attachment/endosure N = No coyOFFICE Tech x HICB* x PECB* DRPMContacts*NAME NFields JWermiel AChaffee MSlosson 5___ __ __ TK oshy _ _ _ _ _ _ _ _ _ _DATE 06/09/97 06/09/97 06/12/97 V07OFFICIAL KRCORU COPY-
E=Copy with attachment/enclosure
IS .--4K-IN 97-xxJune xx, 1997 ~ 6171k


; IK'JIN 97-xxJune xx, 1997 
N = No copy OFFICE Tech x HICB x PECB DRPM Contacts l 4.5-A C)l NAME NFields AT JWermiel J A haffee MSlosson.TKoshyA UW P 67 DATE 61 /97 OF FICAL 7 41 /97 OFFICIAL RECORD COPY}}
}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Revision as of 14:08, 31 August 2018

Level-Sensing System Initiates Common-Mode Faulure of High-Pressure-Injection Pumps
ML031050514
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, 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, 05000349, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Crane  
Issue date: 06/24/1997
From: Slosson M M
Office of Nuclear Reactor Regulation
To:
References
IN-97-038, NUDOCS 9706200203
Download: ML031050514 (7)
v • d • e


UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 June 24, 1997 NRC INFORMATION

NOTICE 97-38: LEVEL-SENSING

SYSTEM INITIATES

COMMON-MODE FAILURE OF HIGH-PRESSURE-INJECTION

PUMPS

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 recent incident in which two high-pressure-injection (HPI) pumps were damaged as a result of an inaccurate

letdown storage tank (LDST) level-sensing

system.The inaccuracy

was caused by a drained reference

leg. As a result, an incorrect

level was displayed, permitting

the pumps to take suction from an empty tank. It is expected that recipients

will review this information

for applicability

to their facilities

and consider actions, as appropriate.

However, suggestions

contained

in this information

notice are not NRC requirements;

therefore, no specific action or written response is required.Descdrition

of Circumstances

On May 3, 1997, the licensee for Oconee Unit 3 was conducting

a planned shutdown to inspect an HPI line. During cooldown of the plant, HPI pump 3B was operating

in the reactor coolant system (RCS) makeup mode. The pump's discharge

pressure dropped to the "low'pressure setpoint initiating

the automatic

start of standby HPI pump 3A. The operators

later secured pump 3A when reactor coolant pump (RCP) seal injection

flow indicated "high". The HPI header pressure decreased

again. HPI pump 3A automatically

restarted.

The pump's motor current began oscillating.

The operators

secured HPI pump 3B because of an indication

of low motor current. Shortly afterwards, HPI pump 3A was also secured when its motor current decreased

sharply. The licensee issued a Notification

of an Unusual Event because of the loss of two of the three HPI pumps.The licensee later concluded

that both HPI pumps became hydrogen bound and possibly damaged when they took suction from an empty LDST even though adequate tank inventory was indicated.

De4e NOrTLdE 1-0o3' 970o6 4 U(WH)oLA .B~O~ 31O1 lMa c rz I -reP Undi aqquafac @)

IN 97-38 June 24, 1997 Discussion

The HPI pumps at Oconee perform the dual functions

of RCS makeup and high-pressure

safety injection.

These pumps normally take suction from the LDST (also referred to as the makeup or volume control tank by other vendors).

A 25-psi (172.4 kPa) hydrogen overpressure

is maintained

in this tank to scavenge oxygen from the RCS.During this event, two level transmitters

monitored

tank level. These transmitters

produce level alarms in the control room. The alarms alert operators

to initiate makeup to the LDST.Both level transmitters

shared a common reference

leg. Because the shared reference

leg was partially

drained, the indicated

letdown tank level remained at 9 inches above the low-level

alarm setpoint.

The tank was actually empty, its contents having been depleted during normal charging.

Letdown tank level was investigated

only after both HPI pumps developed

problems.Indicated

level in the control room was derived from the equivalent

pressure difference

between the drained reference

leg and the back pressure from the 25 psi hydrogen overpressure

in the LDST. Because both level instruments

shared the common reference leg, both gave the same erroneous

indication.

Therefore, operators

failed to provide makeup inventory

to the LDST. Two of the three HPI pumps became gas-bound, cavitated, and, as a result, were structurally

damaged.If an actual safety injection

actuation

occurs, the suction isolation

valve to the LDST remains open while the suction isolation

valve to the borated water storage tank (BWST) opens on the safety injection

signal. All three HPI pumps receive a start signal and take suction on both the LDST and the BWST. With the two tanks cross-tied, the potential

existed for this event to have caused the loss of all HPI pumps as a result of gas binding. Loss of all three HPI pumps could prevent the successful

mitigation

of a loss of coolant accident.

During normal operations, loss of all HPI pumps would result in the loss of reactor coolant pump seal injection, normal RCS makeup, and normal boration.The level transmitters

were last calibrated

in February 1997. Sometime between that last calibration

and the event, a leak developed

from a scored cap on a test connection

that drained the reference

leg. The cap was used to isolate the test connection.

A drained reference

leg or a reference

leg with entrained

air can result in incorrect

level indication.

Incorrect

level indication

will prevent appropriate

setpoints

being reached when process conditions

demand, defeat critical automatic

safety functions, and could mislead plant operators

into taking less than conservative

actions.Pressure and level sensors, in any safety-related

application, that rely on a reference

leg for a differential

pressure reading, are sensitive

to changes in reference

leg level. Normal surveillances

that Include only channel checks with other instruments

sharing the reference leg or transmitter

calibrations

with external hydrostatic

test sets will not reveal the true condition

of the reference

leg. In the absence of an automatic

reference

leg fill system, periodic verification

of reference

leg level based on the plant-specific

environment

is needed to ensure the operational

integrity

of the critical systems that are relied upon for manual and automatic

functions.

IN 97-38 June 24, 1997 This information

notice requires no specific action or written response.

If you have any questions

about information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts:

Thomas Koshy, NRR 301-415-1176 E-mail: txkenrc.gov

Nick Fields, NRR 301-415-1173 E-mail: enfenrc.gov

Attachment:

List of Recently Issue Information

Notices 4' ln.44

I Attachment

IN 97-38.June 24, 1997 LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Information

Date of Notice No. Subject Issuance Issued to 96-53, Supp. 1 97-37 Retrofit to Amersham 660 Posilock Radiography

Camera to Correct Incon-sistency in 10 CFR Part 34 Compatibility

Main Transformer

Fault with Ensuing Oil Spill into Turbine Building 06/23/97 06/20/97 All industrial

radiography

licensees All holders of OLs or CPs for nuclear power reactors 97-36 97-35 97-34 Unplanned

Intakes by Worker of Transuranic

Airborne Radioactive

Materials

and External Exposure Due to Inadequate

Control of Work Retrofit to Industrial

Nuclear Company (INC)IR100 Radiography

Camera to Correct Inconsistency

in 10 CFR Part 34 Compatibility

Deficiencies

in Licensee Submittals

Regarding Terminology

for Radio-logical Emergency

Action Levels in Accordance

With the New Part 20 06/20/97 06/18/97 06/12/97 All holders of OLs and CPs permits. All licensees

of of nuclear power reactors in the decommissioning

stage and fuel cycle All industrial

radiography

licensees All holders of OLs or CPs for test and research reactors OL = Operating

License CP = Construction

Permit

I KU IN 97-38 June 24, 1997 This information

notice requires no specific action or written response.

If you have any questions

about information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.original signed by S.H. Weiss for Marylee M. Slosson, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Thomas Koshy, NRR 301-415-1176 E-mail: txk@nrc.gov

Nick Fields, NRR 301-415-1173 E-mail: enf@nrc.gov

Attachment:

List of Recently Issued NRC Information

Notices Tech Editor has reviewed and concurred

on 5/14197 DOCUMENT NAME: G:XNICKIOCONEE.IN

  • SEE PREVIOUS CONCURRENCES

To receive a co of this document.

indicate In the box C=Coov wlo attachmentlendosure

E=Coov with attachment/endosure

N = No coy OFFICE Tech x HICB* x PECB* DRPM Contacts*NAME NFields JWermiel AChaffee MSlosson 5___ __ __ TK oshy _ _ _ _ _ _ _ _ _ _DATE 06/09/97 06/09/97 06/12/97 V07 OFFICIAL KRCORU COPY-

I S .--4 K-IN 97-xx June xx, 1997 This information

notice requires no specific action or written response.

If you have any questions

about information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts:

Thomas Koshy, NRR 301-415-1176 E-mail: txk@nrc.gov

Nick Fields, NRR 301-415-1173 E-mail: enfenrc.gov

Attachment:

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N = No copy OFFICE Tech x HICB* l x PECB* DRPM Contacts*

ll NAME NFields JWermiel AChaffee MSlosson TKoshy DATE 06/09/97 06/09/97 06112/97 4/ /97 OFFICIAL RECORD COPY~ 6171k

I K'J IN 97-xx June xx, 1997 This information

notice requires no specific action or written response.

If you have any questions

about information

in this notice, please contact on6 of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Marylee M. Slosson, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

Contacts: Thomas Koshy, NRR 301-415-1176 e-mail:txk@nrc.gov

Nick Fields, NRR 301-415-1173 e-mail:enfenrc.gov

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N = No copy OFFICE Tech x HICB x PECB DRPM Contacts l 4.5-A C)l NAME NFields AT JWermiel J A haffee MSlosson.TKoshyA UW P 67 DATE 61 /97 OF FICAL 7 41 /97 OFFICIAL RECORD COPY


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