ML20010G007

Forwards Addl Info Re Snupps Loose Parts Monitoring Sys,Per G Edison Request.Info Will Be Incorporated Into Next FSAR Revision

ML20010G007
Person / Time
Site:	Wolf Creek, Callaway
Issue date:	09/08/1981
From:	Petrick N STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM
To:	Harold Denton Office of Nuclear Reactor Regulation
References
SLNRC-81-91, NUDOCS 8109150223
Download: ML20010G007 (6)

Text

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SNUPPS Stenderdized Nucieer Unit Power Plant System 5 Choke Cherry Road NicFolas A. Petrick Rockville, Maryland 20050 Executive Director (301) 8694010 Septembar 8, 1981 SLNRC 81 91 FILE: 0541 SUBJ: Loose Parts Monitor i 1 SR'iv

r. Harold R. Denton, Director b \

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission 9 Of7))9 Ld_

Washington, D. C. 20555 l SEi'14 O * \-

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Docket Hos. STN 50-482, STN 50-483, and STN 50-486

Dear Mr. Denton:

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In discussions with Dr. Gordon Edison, NRC project manager for the SNUPPS applications, it was determined that additional FSAR documen-

, tation concerning the SNUPPS Loose Parts Monitoring System was required.

The enclosure to this letter provides the requested information and

will be incorporated in the next FSAR revision.

Very ruly yours, Y -CM W \ -

W Nicholas A. Petrick RLS/jdk Enclosure cc: J. K. Bryan UE G. L. Koester KGE D. T. McPhee KCPL D, F. Schnell UE W. A. Hansen NRC/ CAL T. E. Vandel NRC/WC Bool s

,/i 8109150223 810908 DR ADOCK 05000482 PDR

SNUPPS startup sources at an elevation approximately 1/4 of the core height. Two compensated ionization chambers for the intermediate range, located in the same instrument wells and detector assemblies as the source range detectors, are positioned at an elevation corresponding to 1/2 of the core height. Four dual section uncompensated ionization chamber assemblies for the power range are installed vertically at the four corners of the core and are located equidistant from the reactor vessel at all points and, to minimize neutron flux pattern distortions, within

• foot of the reactor vessel. Each power range detector provides two I

signals corresponding to the neutron flux in the upper and in the lower sections of a core quadrant. The three ranges of detectors are used as inputs to monitor neutron flux f7.om a completely shutdown condition to 120 percent of full power with the capability of recording overpower excursionu up to 200 percent of full power.

The output of the power range channels is ased for:

a. The rod speed control function

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b. Alerting the operctor to an excessive power un-balance between the quadrants

c. Protecting the core against the consequences of rod ejection accidents, and

d. Protecting the core against the' consequences of adverse power distributions resulting from dropped rods Details of the neutron detectors and nuclear instrumentation design and the control and trip logic are given in Chapter 7.0. The limits on neutron flux operation and trip setpoints are given in the Technical Specifications.

4.4.6.4 Loose Parts Monitoring System The loose parts monitoring system (LPMS) monitors the re-actor coolant system (RCS) for the presence of metallic loose parts. It consists of 12 active instrumentation channels, each comprising a piezoelectric accelerometer (sensor), signal conditioning, and diagnostic equipment.

The system complies with NRC Regulatory Guide 1.133. l Two redundant sensors are fastened mechanically to the RCS at each of the following potential loose parts collection regions:

Reactor pressure vessel - upper head region Reactor pressure vessel - lower head region Each steam generator - reactor coolant inlet region Rev. 7 4.4-44 9/81

L f+WO SNUPPS The output signal from each accelerometer is amplified by a preamplifier and amplifier. The amplified signal is pro-cessed through a discriminator to eliminate noises and signals not indicative of loose parts, and the processed signal is compared to a preset alarm setpoint. Loose parts detection is accomplished at a frequency of approximately 25 kHz, where bachground signals from the RCS are low. Spurious alarming to control rod stepping or reacter coolant pump startups is prevented by contacts that sense these events and activate alarm disable circuits. g,. ;f ty If a measured signal exceeds the preset ala level,l audible and visible alarms at the LPMS console in th contro] room are activated. The LPMS automatically initi tes recc rding, l on a four-channel tape recorder, the signals rom the alarmed channel and three other channels in p ximity to the a] armed channel. A microprocessor recog rpe% % e first and subsequent impact signals,g,s reach the, times 4;theer various sensors.

This enables thellocation7of the loose part to be determined.

mA The LPMS also has provision for audio monitoring of any channel.

Gyt Audio monitoring, including comparison of the audio signal with a previously recorded " signature" audio signal, if there is an ambiguity, will be performed to confirm the presence of a loose part.

The on-line sensitivity of the LPMS is such that the system will detect a loose part that weighs from 0.25 to 30 pounds and impacts with a kinetic energy of 0.5 feet pounds on the inside surface of the RCS pressure boundary within 3 feet of a sensor.

t The components of the LPMS are designed for the environmental conditions specified in Table 4.4-5. All of the equipment inside the containment is designed to remain functional through an OBE and radiation exposures anticipated during a 40-year operating lifetime. Physical separation of the two instrument channels, associated with the redundant sensors at each RCS location, exists from the sensor to the output of the signcl conditioning devices.

t l The LPMS will be calibrated prior to plant startup by impaXting I

the reactor vessel and steam generators with a calibrated impact device with 0.5 ft-lbs energy 3 feet from each sensor location. The LPMS must produce an alarm under these conditions with a 0.5 ft-lbs alarm setpoint. The preoperational calibration will be performed with the reactor coolant system filled with water at an elevated temperature and will be recorded for analysis and reference audio analysis. Channel audio outputs will l also be recorded during hot functional testing to obtain a

" signature" record, which can subsequently be used for comparison with real or suspected loose perts signals.

Capabilities exist for subsequent periodic on-line channel checks and channel functional tests and for off-line channel calibrations at refueling outages.

Rev. 7 4.4-45 9/81

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g % vtM; Operators will be trained in the operation and maintenance w of the LPMS prior to initial plant startup. This will con-sist of a short formal training session onsiter dekha

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The vendor also can provide service personnel on short notice to assist the operating staff in operation or maintenance ~of the equipment and analysis of loose parts signals, as may be required.

I Rev. 7 4.4-45a 9/81

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. SNUPPS LPhts TABLE 4.4-5 LOOSE PARTS MONITORING SYSTEM Environmental Conditions ,

A. Accelerometers Temperature 40-650 F Humidity 0-100%

Radiation 101snvt and 10s rad Pressure 69 psig Vibration OBE Atmosphere Air B. Preamplifiers and Cables (inside containment)

Temperature-electronics40-150 F Hardline Cable 40-650 F Cable inside 40-150 F containment Humidity 0-100%

Radiation 1012nyt and 6x106 rad Pressure 69 psig Shock and Vibration OBE Atmosphere Air l

C. Signal Conditioning Amplifier, Signal Processor, and Associated Equipment (outside of containment) l Temperature 40-120 F Radiation 103 rad Pressure Atmospheric Humidity 0-95%

Shock and Vibration In accordance with l good engineering practice l

Atmosphere Air Rev. 7 9/81

LPw4J SNUPPS REGULATORY GUIDE 1.131 REVISION O DATED 8/77 Qualification Tests of Electric Cables, Field Splices,. and Connections for Light-Water-Cooled Nuclear Power Plants' DISCUSSION:

The recommendations of this regulatory guide are met with thi exceptions noted in Section 8.1.4.3.

REGULATORY GUIDE 1.132 REVISION 1 DATED 3/79 Site Investigations for Foundations of Nuclear Power Plants DISCUSSION:

Refer to Appendix 3A of each Site Addendum.

s/es REGULATORY GUIDE 1.133 REVISION jfi DATED 9%22; Loose-Part Detection Program for the Primary System of Light-Water-Cooled Reactors DISCUSSION:

The recommendations of this regulatory guide are met.YtW9;A%Q 4. l M t,ds.10 Rribed'i.% Section 4.4.6.4.

REGULATORY GUIDE 1.134 REVISION 1 DATED 3/79 Medical Evaluation of Nuclear Power Plant Personnel Requiring Operator Licenses ,

DI3CUSSION:

Refer to Appendix 3A of each Site Addendum. ,

REGULATORY GUIDE 1.135 R2 VISION O DATED 9/77 Normal Water Level and Discharge at !!uclear Power Plants l

i DISCUSSION:

! Refer to Appendix 3A of each Site Addendum.

REGULATORY GUIDE 1.136 REVISION 1 DATED 10/78 Material for Concrete Containments DISCUSSION:

The recommendations of Section 3.8.1.5 are used in lieu of 8 the recommendations of this regulatory guide, which generally endorses ACI Standard 359-74.

7 3A-45 Rev.h(

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