Information Notice 1995-13, Potential for Data Collection Equipment to Affect Protection System Performance

Potential for Data Collection Equipment to Affect Protection System Performance
	ML031060330
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:	02/24/1995
From:	Crimes B; Office of Nuclear Reactor Regulation
To:	;
References
	IN-95-013, NUDOCS 9502240037
	Download: ML031060330 (8)
	v • d • e

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 February 24, 1995 NRC INFORMATION NOTICE 95-13: POTENTIAL FOR DATA COLLECTION EQUIPMENT TO

AFFECT PROTECTION SYSTEM PERFORMANCE

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

PurDose

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

notice to alert addressees to a potential single or common mode failure when

using devices to collect data on protection system performance. 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

During testing of the main turbine at Fermi 2 after extensive maintenance, the

licensee received spurious high reactor water level alarms on the sequence- of-events recorder for the reactor core isolation cooling (RCIC) system. On

February 10, 1995, a portable computerized data acquisition system (DAS) was

connected to four level instruments and one pressure instrument in each of two

divisional testability cabinets. The DAS consisted of two separate computer

units, with one unit being connected to each testability cabinet so that both

divisions could be monitored simultaneously.

It was assumed that the DAS units were nonintrusive, and no evaluation was

performed in accordance with Section 50.59, "Changes, Tests, and Experiments",

of Title 10 of the Code of Federal Regulations (10 CFR). No detailed testing

of the DAS units was performed to determine potential failure modes or effects

on the instruments to which they were connected. No guidance was given to the

technicians on whether or not to leave the devices connected when they were

deenergized.

Operators in the control room noted that when the DAS units were turned off on

February 11, 1995, the wide range level indication decreased by 25 cm [10

inches]. Investigation by the licensee showed that when the DAS input

multiplexer was energized, the input impedance was in excess of lOOK ohm, but

when it was deenergized, the impedance dropped to approximately 4K ohm. This

phenomenon appears to be an inherent characteristic of the DAS overvoltage

protection circuit, rather than any intenal component failure. The vendor

9502240037 P 001i

01o

IN 95-13 February 24, 1995 manual does not contain a caution about leaving the inputs connected when the

unit is deenergized.

The drop in impedance allowed more current to be drawn from the wide range

level indication circuitry and resulted in the decreased level indication.

Since both units were turned off at the same time, both divisions were

affected.

Discussion

The DAS units used at Fermi 2 are manufactured by Intelligent Instrumentation

and utilize a Model No. PCI-20098C multifunction carrier board. The

overvoltage protection circuit is a common design used in solid state

multiplexers sold by various manufacturers of data acquisition equipment.

This equipment may be widely used in the nuclear power industry to collect

special plant data for analysis of various input parameters.

Although detailed testing of the DAS units was not performed before their use, a routine preconnection test was performed. A digital voltmeter was used to

test the units in both the energized position and the deenergized position, but the voltmeter did not detect the change in input impedance.

At Fermi 2, the DAS units were plugged into test jacks in the testability

cabinets normally used for surveillance testing. This practice is common in

the industry. The bias inserted by the devices when deenergized affected the

autostart and high level trip signals for RCIC and high pressure coolant

injection (HPCI). Additional testing indicated that RCIC and HPCI would

initiate at a level approximately 13 cm [5 inches] higher than expected on low

reactor level and would trip about 43 cm [17 inches] above the expected high

level trip setpoint.

The DAS units were powered by a nonsafety-related source. Although the

technicians turned the units off, the same effect would have been achieved if

the unit suffered a loss of station or offsite power during testing. In

either case, the possibility existed for a common mode error in the low level

initiation and high level trip setpoints for HPCI and RCIC.

Separation of redundant channels of protection systems during testing is

addressed in Regulatory Guide 1.118, "Periodic Testing of Electric Power and

Protection Systems." It states that a temporary test setup shall be

considered a part of the safety system. In addition, the Institute of

Electrical and Electronics Engineers (IEEE) Standard 279-1977, "Criteria for

Protection Systems for Nuclear Power Generating Stations," specifies that a

single failure in the protection system not cause a loss of function, and

redundant channels be independent and physically separated. IEEE Standard

338-1975, "Criteria for the Periodic Testing of Nuclear Power Generating

Station Safety Systems," specifies that test equipment not cause loss of

independence between redundant channels. The licensing basis of each plant

contains the specific applicable commitments for channel independence.

- ~IN 95-13 February 24, 1995 Section 50.59 of 10 CFR requires licensees to provide a basis for the

determination that a test or experiment not described in the safety analysis

report does not involve an unreviewed safety question.

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: Monte Phillips, RIII

(708) 829-9637 David Skeen, NRR

(301) 415-1174 J are-&

t

Attachment: List of Recently Issued NRC Information No ices

fA4W'L r ,S

Attachment

IN 95-13 February 24, 1995 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

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.

95-11 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

95-10 Potential for Loss of 02/10/95 All holders of OLs or CPs

Supp. 1 Automatic Engineered for nuclear power reactors.

Safety Features

Actuation

95-10 Potential for Loss of 02/03/95 All holders of OLs or CPs

Automatic Engineered for nuclear power reactors.

Safety Features

Actuation

95-09 Use of Inappropriate 01/31/95 All holders of OLs or CPs

Guidelines and Criteria for nuclear power reactors.

for Nuclear Piping and

Pipe Support Evaluation

and Design

95-08 Inaccurate Data Obtained 01/30/95 All holders of OLs or CPs

with Clamp-On Ultrasonic for nuclear power reactors.

Flow Measurement Instruments

95-07 Radiopharmaceutical Vial 01/27/95 All USNRC medical licensees

Breakage during Preparation authorized to use byproduct

material for diagnostic

procedures.

95-06 Potential Blockage of 01/25/95 All holders of OLs or CPs

Safety-Related Strainers for nuclear power reactors.

by Material Brought Inside

Containment

OL = Operating License

CP = Construction Permit

IN 95-13 February 24, 1995 Section 50.59 of 10 CFR requires licensees to provide a basis for the

determination that a test or experiment not described in the safety analysis

report does not involve an unreviewed safety question.

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. orig /s/'d by BKGrimes

Brian K. Grimes, Director

Division of Project Support

Office of Nuclear Reactor Regulation

Technical contacts: Monte Phillips, RIII

(708) 829-9637 David Skeen, NRR

(301) 415-1174 Attachment: List of Recently Issued NRC Information Notices

DOCUMENT NAME: 95-13.IN

Soa nvreviniu roncuirrence

OFC OECB:DOPS SC/OECB:DOPS PUB:ADM RIII

NAME DSkeen* RDennig* MMejac* MPhillips*

DATE 02/22/95 02/23/95 02/22/95 02/22/95 OFC SC/HICB OECB:DOPS C/OECB:DOPS D

NAME JMauck* RKiessel* AChaffee* di_____m__Vs

DATE 02/23/95 02/23/95 02/23/95 02/ /95 OFFICIAL RECORD COPY

IN 95-XX

February xx, 1995 The drop in impedance allowed more current to be drawn from the wide range

level indication circuitry and resulted in the decreased level indication.

Since both units were turned off at the same time, both divisions were

affected.

Discussion

The DAS units used at Fermi 2 are manufactured by Intelligent Instrumentation, and and utilize a Model No. PCI-20098C multifunction carrier board. The

overvoltage protection circuit is a common design used in solid state

multiplexers sold by various manufacturers of data acquisition equipment.

This equipment may be widely used in the nuclear power industry to collect

special plant data for analysis of various input parameters.

Although detailed testing of the DAS units was not performed before their use, a routine preconnection test was performed. A digital voltmeter (DVM) was

used to test the units in both the energized position and the deenergized

position, but the DVM did not detect the change in input impedance.

At Fermi 2, the DAS units were plugged into test jacks in the testability

cabinets normally used for surveillance testing. This practice is common in

the industry. The bias inserted by the devices when deenergized affected the

autostart and high level trip signals for RCIC and high pressure coolant

injection (HPCI). Additional testing indicated that RCIC and HPCI would

initiate at a level approximately 12 cm [5 inches] higher than expected on low

reactor level and would trip about 43 cm [17 inches] above the expected high

level trip setpoint.

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: Monte Phillips, RIII David Skeen, NRR

(708) 829-9637 (301) 415-1174 Attachment: List of Recently Issued NRC Information Notices

DOCUMENT NAME: G:\DLS\IN95-XX.DAS

See Previous concurrence

OFC OECB:DOPS SC/OECB:DOPS PUB:ADM RIII

NAME DSkeen* RDennig* MMejac* MPhillips*

DATE 02/22/95 02/23/95 02/22/95 J02/22/95 OFC SC/HICB OECB:DOPS C/OECB:DOPS D/DOPS

NAME JMauck* RKiessel* AChaffee* BGrimes