Information Notice 1985-02, Improper Installation and Testing of Differential Pressure Transmitters

Improper Installation and Testing of Differential Pressure Transmitters

ML031180750
Person / Time
Site:	Beaver Valley, Millstone, Hatch, 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, 05000000, 05000262, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Skagit, Marble Hill
Issue date:	01/11/1985
From:	Jordan E NRC/IE
To:
References
IN-85-002, NUDOCS 8501080502
Download: ML031180750 (3)

SSINS No.: 6835 IN 85-02 UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 January 11, 1985 IE INFORMATION NOTICE NO. 85-02: IMPROPER INSTALLATION AND TESTING OF

DIFFERENTIAL PRESSURE TRANSMITTERS

Addressees

All nuclear power reactor facilities holding an operating license (OL) or a

construction permit (CP).

Purpose

This information notice provides notification of a potentially significant

problem pertaining to the improper installation and inadequate functional

testing of differential pressure transmitters. Such conditions occurred at the

McGuire Nuclear Station, Unit 1, when the Barton differential pressure switches

utilized to control the isolation valves of the upper head injection (UHI)

system were replaced with Rosemont differential pressure transmitters. It is

expected that recipients will review the information contained in this notice

for applicability to their facilities and consider actions, if appropriate, to

preclude similar problems from occurring at their facilities. However, sugges- tions contained in this notice do not constitute NRC requirements; therefore, no specific action or written response is required.

Description of Circumstances

On November 1, 1984, Duke Power Company informed the NRC that the UHI isolation

valves failed to close when the UHI water accumulator was drained at its

McGuire Nuclear Station, Unit 1. At that time, the plant was shut down because

the nitrogen content of the water in the UHI accumulator exceeded the limit

permitted by its technical specifications. Subsequent investigations revealed

that the four differential pressure transmitters used to sense the level of

water in the UHI accumulator and initiate automatic closure of the isolation

valves on a predetermined level had been improperly installed. As a result, the isolation valves did not automatically close when the water level in the

UHI accumulator reached the set point.

The McGuire UHI system design includes a separate nitrogen accumulator that

supplies pressurized nitrogen to force the water from the UHI water accumulator

into the reactor vessel during the initial phase of a design-basis loss-of- coolant accident (LOCA). Thus, if the UHI isolation valves fail to close

during the course of a design-basis LOCA, nitrogen could be injected into the

reactor vessel. To prevent such an event, the differential pressure transmit- ters are designed to initiate automatic closure of the UHI isolation valves

when the water in the UHI accumulator reaches a predetermined level.

8501080502

'-I/

IN 85-02 January 11, 1985 During April of 1984, the McGuire'Nuclear Station, Unit 1, Barton reverse-acting

differential pressure switches were replaced with Rosemont direct-acting

differential pressure transmitters to improve the accuracy andrepeatability of

the UHI water accumulator level sensing system. However, the Rosemont:differential

pressure transmitters were not properly installed in that the impulse lines

were not connected to the appropriate transmitter ports. Several factors

contributed to the improper installation, including inadequate installation

instructions. The major contributor was inadequate functional testing of the

UHI system after it had been modified in that the post-modification tests

were limited to calibration tests of the differential pressure transmitters.

These calibration tests were performed with the transmitters isolated from the

impulse lines. Consequently, the tests only verified that the transmitters

would provide the required output signal for a given differential pressure, but

they did not demonstrate that the transmitters sensed the differential pressures

associated with water level changes in the UHI water accumulator. Thus, the

differential pressure transmitters were not only improperly installed, but the

error was not detected until this event. If a design-basis LOCA had occurred

during this period, the UHI system would have been actuated, but the UHI

isolation valves would not have closed when the water in the UHI water accumulator

had been depleted and nitrogen gas could have been injected into the reactor

vessel during the course of the LOCA.

Similar installation errors have been addressed in IE Information Notice No.

84-45,--'ReversedDifferentia-l-Pressure-Instr-ument-LFnes-LHowever-,-the majority--

of events described in that information notice occurred in boiling water

reactors during plant construction and were detected by functional tests

performed before commencing power operation. In contrast, the event described

in this information notice occurred at a pressurized;water reactor and was

undetected during approximately 5 months of power operation.

No specific action or written response is required by this information notice;

however, if you have any question regarding this notice, please contact the

Regional Administrator of the appropriate NRC regional office or the technical

contact listed below.

Z oNnDr

Divisio Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

I. Villalva, IE

(301) 492-9007 F. R. McCoy, RII

(404)221-2689 Attachment:

List of Recently Issued IE Information Notices

Attachment

IN 85-02 January 11, 1985 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject - Issue Issued to

85-01 Continuous Supervision of 1/10/85 All material licensees

Irradiators possessing irradiators

that are not self- shielded and contain

more than 10,000

curies of radioactive

material

84-94 Reconcentration Of Radio- 12/21/84 All NRC materials

nuclides Involving Discharges licensees other than

Into Sanitary Sewage Systems licensees that use

Permitted Under 10 CFR 20.303 sealed sources only

84-93 Potential For Loss Of Water 12/17/84 All power reactor

From The Refueling Cavity facilities holding

an OL or CP

84-92 Cracking of Flywheel on 12/17/84 All power reactor

4 II ... k .. ,-Cummins Fire Pump Diesel s.. e - I1e . . .. .facilities holding

Engines an OL or CP

84-91 Quality Control Problem 12/10/84 All power reactor

Of Meteorological facilities holding

Measurements Problems an OL or CP

84-90 Main Steam Line Break 12/7/84 All pressurized

Effect On Environmental water reactor and

Qualification Of Equipment gas cooled power

facilities holding

an OL or CP

84-89 Stress Corrosion Cracking 12/7/84 All boiling water

In Nonsensitized 316 reactor facilities

Stainless Steel holding an OL or CP

84-88 Standby Gas Treatment 12/3/84 All boiling water

System Problems reactor facilities

holding an OL or CP

OL = Operating License

CP = Construction Permit