ML20080Q900

Forwards Draft FSAR Changes to Appear in Feb FSAR Rev Re SER (NUREG-0991) Section 4.4.6, Loose Parts Monitoring Sys, Table 4.1.Addl Info Requested in Table 4.1 Should Satisfy SER Confirmatory Issue 11

ML20080Q900
Person / Time
Site:	Limerick
Issue date:	02/21/1984
From:	Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Schwencer A Office of Nuclear Reactor Regulation
References
RTR-NUREG-0991, RTR-NUREG-991 NUDOCS 8402270166
Download: ML20080Q900 (21)

Text

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h PHILADELPHIA ELECTRIC COMPANY 23O1 MARKET STREET P.O. BOX 8699 i

1881 1981 PHILADELPHIA PA.19101 JOHN S. KEMPER 1 1. S*.I."I?!1".L.c February 21, 1984 Mr. A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing U. S. Nuclear Regulatory Ccmnission Washington, D.C. 20555

Subject:

Linerick Generating Station, Units 1 and 2 Core Performance Branch Icose Parts Monitoring System Confirmatory Issue #11

Reference:

E. J. Bradley to A. Schwencer letter dated June 27, 1983.

File:

GOVT l-3 (IEC)

Dear Mr. Schwencer:

The Linnrick Generating Station Safety Evaluation Report (SER),

NUREG-0991, Section 4.4.6, " Loose Parts Monitoring Systcan", Table 4.1, lists the NRC staff's findings in regards to Regulatory Guide conformance and areas for which additional information is required.

Attachment A, consists of draft FSAR page changes to Chapter 4 wilich will appear in the February revision of the PSAR.

It addresses iterns C.1, C.2, C.3(b), C.4 (except C.4.i), C.5 and C.6 of SER Table 4.1.

Attachment B, "Cament Reganling the II;3 Icose Parts Monitoring System Catpliance with Regulatory Guide 1.133 (Revision 1, May,1981)", addresses items C.3(a) and C.4.1 of SER Table 4.1.

Attach: Tent B will not be incorporated into the FSAR.

Attachments A and B provide all the additional information requested in Table 4.1.

They should satisfy Confirmatory Issue #11 of the safety Evaluation Report.

Sincerely, CMf,C[

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RJS/gra/012484215 cc: See Attached Service List Y o - 3.S g NJ f

8402270166 840221 PDR ADOCK 05000352 E

PDR

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r cca Judga Lawrence Brenner (w/ enclosure)

Judge Peter A. Morris (w/ enclosure)

Judge Richard F. Cole (w/ enclosure)

Troy B. Conner, Jr., Esq.

(w/ enclosure)

Ann P..Hodgdon, Esq.

(w/ enclosure)

Mr. Frank R.

Romano (w/ enclosure)

Mr. Robert L. Anthony (w/ enclosure Mr. Marvin I. Lewis (w/ enclosure)

Charles W. Elliot, Esq.

(w/ enclosure)

Zori G. Ferkin, Esq.

(w/ enclosure)

.Mr.. Thomas Gerusky (w/ enclosure)

Director, Penna. Emergency (w/ enclosure)

Management Agency Mr. Steven P. Hershey (w/ enclosure)

Angus Love, Esq.

(w/ enclosure)

Mr. Joseph H. White, III (w/ enclosure)

David Wersen, Esq.

(w/ enclosure)

Robert J. Sugarman, Esq.

(w/ enclosure)

Spence W.

Perry, Esq.

(w/ enclosure)

Jay M. Gutierrez, Esq.

(w/ enclosure)

Atomic Safety & Licensing (w/ enclosure)

Appeal Board Atomic Safety & Licensing (w/ enclosure)

Board Panel Docket & Service Section (w/ enclosure)

Martha W. Bush, Esq.

(w/ enclosure)

James Wiggins (w/ enclosure) r 1

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CHAPTER 4 1

TABLES (Cont'd) l Table Title l

4.3-4 Delsted l

4.3-5 Calculated Neutron Fluxes (Used to Ivaluate Vessel Irradiation) 4.3-6 Calculated Neutron Flux at Core Equivalent Boundary 4.3-7 Calculated Core Effective Multiplication and Control System Worth - No Voids, 200C u

4.4-1 Thermal and Hydraulic Design Characteristics of the Reactor Core 4.4-2 Deleted l

4.4-3 Axial Void Fraction Distribution 4.4-4 Axial Flow Quality Distribution 4.4.5 Axial Power Distribution Ur,ed to Generate Void and Quality Distributions j

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4.4-10 Reactor Coolant System Geometric Data 4.4-11 Safety Injection Line Lengths 4.4-12 Bypass Flow Paths 4.4-13 Stability Analysis Results l

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rate.

Again, no control rods are moved to accomplish the power reduction.

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Varying the recirculation flow rate (flow control) is more advantageous, relative to load following, than using control rod positioning.

Flow variations perturb the reactor uniformly in l

the horizontal planes and ensure a flatter power distribution and l

reduced transient allowances.

As flow is varied, the power and void distributions remain approximately constant at the steady-state end points for a wide range of flow variations.

After adjusting the power distribution by positioning the control rods at a reduced power and flow, the operator can then bring the reactor'to rated conditions by increasing flow, with the assurance that the power distribution will remain approximately constant.

Section 7.7 describes how recirculation flow is varied.

4.4.3.6, Thermal and Hydraulic Characteristics Summary Table p!j The thermal-hydraulic characteristics are provided in Table 4.4-1 for the core and in tables of Sections 5.1 and 5.4 for other portions of the reactor coolant system.

4.4.4 EVALUATION Refer to subsection A.4.4.4 of GESTAR II (Ref. 4.1-1).

The results of the cycle-1 stability analysis are given in Table 4.4-13 and Figures 4.4-7 through 4.4-10.

e 35 4.4.5 TESTING AND VERIFICATION l

Refer to subsection A.4.4.5 of GESTAR II (Ref. 4.1-1).

4 4.4.6 INSTRUMENTATION REQUIREMENTS The reactor vessel instrumentation monitors the key reactor vessel operating parameters during planned operations.

This ensures sufficient control of the parameters.

The reactor vessel sensors are' discussed in Sections 7.6 and 7.7.

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( 1981) of Regulatory G 4.4.6.1.2

System Description

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TheAfunction of this system is to detect and alarm for loose parts in the reactor coolant system.

Loose parts are those metallic objects that can be physically moved by the reactor

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withstan he SSE an re redunda (eight s ors lo ed on opposit sides of h reactor four el tions).

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t A primary consideration in the design of the LPMS is the power spectrum density (PSD) plot shown in Figure 4.4-19, which illustrates the normal background energy content over a specific band of frequencies of an operating power reactor, as detected by l

a piezoelectric transducer.

The overall energy cont,ent and shape of the plot varies with plant conditions and between different sensor locations.

Salient features demonstrated by the PSD are:

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0 4.4.6.1 Loose Parts Monitoring System (LPMS) 4.4.6.1.1 Design Basis a.

The LPMS is designed in conformance with Regulatory Guide 1.133 Rev.

1, May 1981 to continuously monitor the reactor and the reactor coolant system for indication ofM oose parts.

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The LPMS ir d::ign:d ic provide early detection and operator warning of loose parts in the primary system to avoid or mitigate safety-related damage to or mal-functions of primary system components.

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r; design e h.sh7 vads provide for the inclusion of electronic features to minimize operator interfacing requirements during normal operation and to enhance the analysis function when operator action is required to investigate potential loose parts.

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Each unit is provided with a separate LPMS.

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8 Twisted-shielded pair (TPS) cables 5) 8 Noise Signal conditioners 6) 8 Automatic Gain Controls (AGC) 7)

1 Multiplexed Analog Recording and Switching Sub-system (MARSS) 8)

1 Audio Monitor 3e 9) 1 Digital Loose Part Locator (DLPL) jf s.

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High-frequency energy is related to flow associated noises c.

Relatively rapid attenuation of the higher-frequency noises occurs because of the filtering eff t of the acoustic path through the NSSS components.

The LPMS incorporates tuned bandpass filters to concentrate on the portion of the noise spectrum that has a low background level, generally in the 1 Khz to 10 Khz frequency range.

Because metal-to-metal impact esult in a relatively flat frequency response in the 1 OKhz range and because certain portions of the background noise in that portion of the frequency spectrum are of i

relatively low level, the signal-to-noise ratio is improved, thereby enhancing detection capability while reducing the occurrence of false alarms.

The LPMS e6ee incorporates.an automatic gain control (AGC)

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circuit, which normalizes the background level without operator interaction.

This results in a varying threshold detection level that is a function of background noise level produced by changing"C "19 j

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operating power levels and/or configurations.

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alarms by reducing sensitivity at high background levels.

Conversely, at low background levels, sensitivity, and thus detection capabilities, are greatly improved.

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Thib The detector module initiates a high alarm (alert function) when gy:A aJaignal is received that exceeds the setpoint.

There is no fixed setpoint for the detector modules in terms of an absolute energy level because they employ an automatic gain control 33" system, which varies channel sensitivity as a function of the 3

3 background noise level for that channel.

Typically, the system operates at a variable sensitivity of better than 0.5 ft-lbs, and the high alarm (Icose part alert) is initiated when an impact of 120 to 200% of the background energy level is detected.

The detector module also features a low alarm, which is associated wit %thecontinuouschannelcheckfunction.

The low alarm output from the detector modules is routed to the master alarm module only.

The high alarm output of the detector modules is routed to four places:

the master alarm module, the loose parts locator, the matrix switch, and the MARSS.':..;;.yl.. J. l, C 2:n; :n3 C_.tch:n; Cyrt:-

The master alarm module accepts the high and low alarm outputs of the detectors, illuminates an indicator for the appropriate alarm, and initiates argatrdTcJalarm.

Au bt 6tG The loose parts locator is a digital processor that calculates and displays the time of arrival of each loose part impact at the sensors, thereby assisting the operator in determining the g

location of the loose part.

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n na_t The sensors used in the LPMS are woey sensitive to vibrationf over a wide frequency band, thus ideal for detecting acoustic waves transmitted due to impact of Loose Parts (LP) to the reactor internal structure.

p The sensors are mounted at strategic Locations (see section 4.4.6.1.3) immediately outside the reacto

-and connected to the respective remote charge preamplifiers with low noise hardline special cables.

The rem t charge pr9 Amplifier is an active device, powered by 30 C supplied from the signal conditioner via TPS cables.

The remote charge preamplifier superimposes an a-c signal proportional to the accelerometer output on the d-c voltge.

The signal conditioner detects the superimposed a-c signal on the d-c signal and amplifies and normalizes the a-c signal appropriately.

The output of the somete charge pry %mplifier is transmitted to the control room,e..J... m m m.~.. s as i m r ::: TCP ovie.

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The MARSS provides for the recording of signals as manually selected by the operator during routing system operability checkout.

However, when an alarm (alert) condition is detected, MARSS automatically overrides the manually selected inputs and records the alarm channel and three others selected by the alarm matrix.

The tape recorder is a four-track audio tape recorder that records the loose part signals and an encoded channel identification.

The system is designed to operate continuously without operator supervision, except for routine system testing, limiting concljb3 6M

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Q arr-ohumed 4.4.6.1.

Safety Evaluation The LPMS is intended to be used for information purposes only and is not a safety-related system.

The system conforms with Regulatory Guide 1.133.

The plant operators use the LPMS to assist in the detection of anomalous loose parts.

They also use it to assist in determining the location of any anomalous loose parts.

The operators do not rely solely on this system or information provided by this system for the performance of any safety-related action.

Any evaluations or actions taken to confirm the presence of a loose part will be handled on a case-by-case basis.

4.4.6.1.h LPMS Training and Calibration 4.4.6'.1.k.1 LPMS Training The scope of training for the onsite LPMS witt coversthe theory and operation of the LPMS system including hands-on training.

Emphasis C l b: placed on detection and characterization of loose parts and implementation of diagnostic concepts.

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Sensor location:

Eight piezoelectric accelerometers are mounted strategically; two on each of the followingfournaturalcollec'tionregionsf7tocover the whole reactor coolant boundary:ySec igure -

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Vessel Bottom:

Two sensors are mounted on two of the control rod drive housings, immediately outside of the Reactor Vessel bottom.

The control rod housings c'noosen are at 90' and 270' to provide maximum distributed coverage of this region.

2)

Recirculation Water Pump Inlet Lines:

Two sensors are mounted on the two recirculation water pump inlet lines, immediately outside the shield wall.

The recirculation line are located at O' and 180',

which provides distributed coverage of this region.

3)

Feedwater Inlet Nozzles:

Two sensors are mounted on the feedwater nozzles, immediately outside the shield wall.

The feedwater nozzles chosen are at 30' and 210' to provide the maximum distributed coverage of this region.

4)

Steam Outlet Lines:

Two sensors are mounted on the steam outlet lines, immediately outside the JeevLU1 4 84' cEy..:.el wall.

The steam lines chosen are at 108' and 288' to provide the maximum distributed coverage of this region.

b.

System Sensitivity:

Theodhinesensitivityofthe system is such that, as a minimum, the system can detect a metallic loose part that weighs from 0.25 to 30 pounds and impacts with a kinetic energy of 0.5 ft-lb on the inside surface of the reactor coolant pressure boundary within 3 feet of a sensor.

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The impact signal to background ratio is opt mized using the noise filtering techniques, which increases the system's sensitivity and reduces the likelihood of false alarms.

The AGC maintains the background noise at a constant level, relative._to th/reshold level.

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Channel Separation:

The monitoring channel for each sensor is physically separat d from each other, beginning from the sensor u

,o and including the control room monitors, whic contain the alarm circuit, and is always accessible for maintenance during full power operation.

d.

Data Acquisition System:

The system design for the data Acquisition includes sensors, special coaxial cable, preamplifiers, signal conditioner, AGC, DLPL, MARSS_four track audio tape recorder with simultaneous audio and visual alarmy on the system annunciator.

The system design has[Tapability of manual mode pre-operational testing, startup and power operation to establish alerts level.

A004Li In the event the alert leve is reached or exceeded, the system overrides manual operation and activates gyg automatically the visual an audi@ alarms invcontrol The system hasi"dapability to record simultaneously room.

signal $from four sensors, one alarming signal and three -

signal 5 selected from other sensors.

Storage of Data for Comparison - g tape recorder [ility w+M provide 5the necessary recordin eproduction capab of baseline signature or unusua events.

Significant departure from the baseline tape may indic (9,,tpe y, pgggfnef 7 presence of an unusual noise.

This she+ta scertain whether the departure is due to electrical noises which are found to be periodic in nature and have individual wave forms or mechanical noises which are TH6 result of the normal plant operation.

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Alert level:

Provisions bs made to incorporate reference signgal into the LPMS that would indicate a

gg.ng J r/wwg alert level uue to presence of a loose part.

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Capability fgg fensor Channel Operability Test:

Provisions Mm.2ebe-made for periodic on-line channel check and channel functional tests and for off-line channel calibration during periods of cold shutdow or refueling h /nv o cla {c, p.tfn mity <A<.s%vt dw-N

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DBE, there was no evidence of mechanical damage, deterioration or loss of ability to operate during or after the test with exception of the recording devicep'.

The environmental design data are shown in Table 4.4-6, h.

Quality of System Components:

The system component 5 are ci th; state of the art electronics and transducers with proven performance in other similar applications.

Though 40 years life'cannot be assured, the components are replaceable.

A replacement program shall be established for those components which have limited lifeexpeg'tancy.

i.

System Repairs:

The modular ccnfiguration allows a failed module to be replaced, the channel recalibrated, and, returned to operation with ease and without defenerging the system.

All module components are interchangeable and allow repairs to be made at the module, card, or component level.

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/3'bc.% uno Normal System Operation s The-LPMS. M ll he ret to alarm for detected moises,having ~th chagacteristics of metal-to-metal impacts. '_ -

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A loose part~is. considereCto be a metallic object that can be physically' moved by fluid flow.

In general, loose parts are classified-into two generic categories, captive and free.

Captive-loose:partsTare the result of an unanticipated mechan-ical failure yhich causes a setallic object to impact its surrounding structures without being pbysically severed from its original siructure.

Free' loose parts, on the other hand, are free to migrate from one' physical location to another.

- This movement of the :netallic:.ohjeet is. caused by its suspen-sion in the suriounding primarysfluid.

The primary concern of loose parts entrappedsin a high-velocity fluid system is the potential severe. mechanical damage that may result if the metallic object'is allowed %to impact structures.

Metal-to-metal impacts resulting from loose parts excite the

. preferential ringing' mopes of the NSSS components.

The modes are typically between 16Ynd -10 kHz and are easily detected by externally mounted accelerometers.

After inst,- Mtion. of a strategically located accelero:teter array, as identified above, the overall and individual channel characteristics o'f-the accelerometer system will be determined before operation; monitoring.

The LPMS inclu3es provisions for analysis and diagnostic data acquisition cap' abilities, - such as:

Pfchlem ' verification '- false or real alarm a.

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Data gathering - tranhient or' unusual plant condi-

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Once operations of the Nsss have commenced, each accelerometer channel will exhibit its own particular and unique frequency This frequency signature, or normal background, spectrum.

results' from such internal sources as primary flow turbulence, l

gecirculation pump vibrations, feedwater and steam flow tur-bulence, structural responses of M555 components and secondary plant equipment, and a host of other localized noise sources..

In addition, external sources, such as airborne noises from fans and other equipment, contribute to the overall background.

To achieve more reliable detection of unusual noises indica-tive of metal-to-metal impact, a spectral comparison of the measured local metal-to-metal acoustical resonances and the normal background will be performed.

Based on the spectral comparison, the broad-band signal is band-limited to the portion of the spectra that maximizes the signal-to-noise ratio.

This band-limited signal, which in most cases elimi-nates or minimizes the contributions of normal acoustical l

background, is then monitored for sudden transients indicative of metal-to-metal impacts.

A transient must exceed a thresh-old which is a function of the plant background noise level before it can activate the alarm circuitry.

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level is derived in an RMS converter" circuit having a time constant long enough to be largely unaffected by rapid tran-sients and therefore always proportional to the background g

Normal plant transients-cause a shift in the back-level.

ground level and will not activate the alarm circuitry, thereby affecting a reduction in spurious alarms.

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once an unusual noise characteristic of a metal-to metal impact is detected by the loose parts monitor, it is essential to determine the source or cause of the alarm.

The first and simplest form of diagnosis is audio interpretation. but this method is very subjective and can result in a nurnber of erre-neous conclusions to the uneducated listener.

Background

noises, such as throttled steam and flow turbulence. can be l

easily distinguished.

Metal-to-metal impacts can also be readily recognized because of their characteristic spectral l

content.

In addition, the metal-to-metal impacts caused by a bona fide loose part will occur with a random repetitious Further insight can be gained by using a real-time rate.

spectrum analyzer, observing the transient spectra of the impact, and comparing the transient spectrum to known metallic impact and background spectra.

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_-;sL4.4.6.1./.2 LPMS Calibration The LPMS calibration is in accordance wfth Regulatory Guide j

1.133.

The calibration is performed both at cold plant shutdown with no background noise sources (pumps, fans, etc) and with the plant running at maximum power levels.

Calibrated impact hammers are used.

Data is taken at various impact levels at various locations relative to each sensor.

The data obtained provide information to determine the following system characteristics to be used as baseline for plant operations:

a.

. Channel sensitivity or minimum loose part impact to cause alarm (Alert Level) b.

Time and frequency responses to impact c.

Delay time matrix for LPMS sensor array with impacts at various locations.

d.

Impact energy versus channel output amplitude.

T 4.4.6.1.

3 Acceptance Criteria Lese _ Pne.s Hoditov;rog

&Wthth E\\/ALUATtorG No specific acceptance criteria is specified.

Suffici t quality data is recorded to satisfy the objectives listed.

The procedure provides guidelines to ensure the quality and quantity of data to achieve those objectives; however, it is the responsibility of the field engineer in charge to determine the point at which sufficient data has been acquired and when the procedure should be terminated.

The procedure is intended to be used at thb beginning of plant life to establish the system sensitivity.

More abbreviated tests may be performed on a periodic basis to demonstrate that the system response (and sensitivity) is unchanged.

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LG FSAR TABLE 4.4-6 LPMS EQUIPMENT ENVIRONMENTAL DESIGN

-Equipment Environmental Design

1. - Accelerometers Vibration:

500g peak Shock:

3,000g peak Temperature:

-65 to 700 F RcLdbbe, Humidity:

Sealed by glass-to-metal fusion and welding Integrated Gamma 6.2 x 10 10 rad flux:

Integrated Neutron 3.7 x 10 18 n/cm2 flux:

2.

Hardline cable

,. Temperature:

-300 to 900 F lbLAb ve,Humdity:

100% noncondensing Materials:

Stainless steel and magnesium oxide hardened against radiation 3.

treamplifier Temperature:

0 to 160 F Thtqt,Ee,Humidit y:

100% noncondensing 4.

-Control room Temperature:

40 to 100 F operating, equipment la-b've 75 F normal midity:

20 to 80%#;1 abommodate I

brief periods of higher humidity, but not con-

.tinuous higher humidity Pressure:

Atmospheric 50T normal, free of salt or industrial pollutants o

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O COMMENT REGARDING THE LGS LOOSE PARTS MONITORING SYSTEM COMPLIANCE WITH REGULATORY GUIDE 1.133 (REVISION 1, MAY, 1981)

SECTIONS C.3.a AND C.4.i The NRC Regulatory Guide 1.133 describes a method acceptable to the NRC staff for' implementing requirements with respect to detecting a potentially loose part in a light water cooled reactor during normal operation.

The purpose of this document is to outline on a point-by-point basis the content of the Regulatory Guide (dated May, 1981) Sections C.3.a and C.4.1 as it relates to the Limerick Generating Station Loose parts Moni toring System (LPMS).

REGULATORY GUIDE 1.133 LOOSE PART DETECTION FOR THE PRIMARY.

SYSTEM OF LIGHT-WATER-COOLED REACTORS C.

REGULATORY POSITIONS 3.

USING THE DATA ACQUISITION MODES Tile LOOSE-PART DETECTION PROGRAM SHOULD INCLUDE DATA ACQUISITION IN AUTOMATIC AND MANUAL MODES.

THE AUTOMATIC MODE IS FOR CONTINUOUS, ONLIhT DETECTION OF LOOSE @6 HTS.

THE MANUAL MODE IS TO BE USED PERIODICALLY FOR DETECTING LOOSE PARTS, DETERMINING SYSTEM OPERABILITY (INCLUDING CALIBRATION), ESTABLISHING THE ALERT LEVEL, AND DETECTING SIGNIF! CANT SAFETY-RELATED TRENDS IN THE SENSOR SIGNALS AND FOR DIAGNOSTIC PURPOSES.

a.

MANUAL MODE In this mode, the analyst may select any combinations of sensors for data recording and evaluation.

THIS MODE OF DATA ACQUISITION SHOULD BE USED AT THE FOLLOWING TIMES FOR THE INDI CATE D P URP OS E.

no/10/19/83 Page 1 of 5

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(1)

PREOPERATIONAL TESTING:

ESTABLISH ALERT LEVEL FOR THIS TEST PHASE.

The LPMS manufacturer (Babcock & Wilcox) will provide interim setpoints for use prior to startup. sThese setpoints will be used to help establish an alert level for this test phase.

(2)

STARTUP AND POWER OPERATION (a)

ESTABLISH ALERT LEVELS FOR STARTUP AND POWER OPERATION.

THE ALERT LEVEL FOR POWER OPERATION SHOULD BE SUBMITTED TO THE COMMISSION (IN THE STARTUP REPORT WHEN ONE IS PROVIDED)

WITHIN 90 DAYS FOLLOWING COMPLETION OF THE STARTUP TEST PROGRAM IF THE ALERT LEVEL IS FOR POWER OPERATION FOLLOWING INITIAL STARTUP OR THERE IS A CHANGE TO THE PREEXISTING ALERT LEVEL FOR POWER OPERATION.

TEMPORARY CHANGES TO THE ALERT LEVEL NEED NOT BE REPORTED.

The alert level for power operation will be established during power ascention testing and will be submitted to the Commission within 90 days following completion of the startup test program.

3 (b )

AT LEAST ONCE PER 24 HOURS:

PERFORM CHANNEL CHECK.

A channel check will be performed at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> as part of ST-6-107-590-1.

The basic system function may be evaluated from the front panel by an operator in four ways; (1) bias

level, (2) high alarm status and set poin,t; (3) low alarm status (may be. checked by pressing the appropriate front panel buttons and verify)ina the read' on ch module anui (4 the dua channel audio monitor.perrit Ah au dio check for " normal" system noise oD If there is doubt regarding what " normal" noise for that channel is, a no/10/19/83 Page 2 of 5

e-4 reference tape may be replayed for comparison.

Low Alarm function can be verified from the rear of each detector module by~ removing the signal input.

(c)

AT LEAST ONCE PER 7 ' DAYS :

LISTEN TO AUDIO PORTION OF SIGNALS FROM ALL RECOMMENDED SENSORS FOR THE PURPOSE OF DETECTING THE PRESENCE OF LOOSE PARTS.

IF SIGNALS INDICATE THE PRESENCE OR POSSIBILITY OF A LOOSE PART, STATION PERSONNEL SHOULD ACTUATE THE DATA ACQUISITION SYSTEM TO OBTAIN DATA FOR FURTHER 4

EVALUATION.

4 The dual channel audio monitor permits an audio check for " normal" system.

.If there is doubt regarding what " normal" noise for that channel

~ is, a reference tape may be replayed for comparison.

(d)

AT LEAST ONCE PER 31 DAYS:

PERFORM CHANNEL FUNCTIONAL TESTS.

The channel functional test will be performed at least once per 31 days as per ST-6-036-300-1.

The basic system function can be evaluated just as listed for "b" above.

In additi3n, the control room amplifier' gains and. alarm f unctions mayf be tested by injecting a signal into the calibration port on the back of the amplifier modules.

The calibration signal can be f rom a f unction generator or f rom a specially prepared calibration tape.

(e)

AT LEAST ONCE PER 92 DAYS :

VERIFY THAT THE BACKGROUND NOISE MEASURED DURING NORMAL PLANT OPERATION IS SUFFICIENTLY SMALL THAT THE SIGNAL ASSOCIATED ~ WITH THE SPECIFIED DETECTABLE LOOSE-PART IMPACT WOULD BE CLEARLY DISCERNIBLE IN THE PRESENCE OF THIS BACKGROUND NOISE.

VERIFY THAT THE SIGNAL FROM EACH no/10/19/83 Page 3 of 5

~

RECOMMENDED SENSOR DOES NOT FALSELY INDICATE THE PRESENCE OF A LOOSE PART.

THIS SHOULD INCLUDE COMPARISON WITH DATA, INCLUDING AUDIO DATA, OBTAINED AT THE TIME OF THE LAST TWO QUARTERLY MEASUREMENTS TO VERIFY THAT THERE DOES NOT EXIST A SIGNIFICANT TREND OR ANOMALY THAT MAY FALSELY INDICATE THE PRESENCE OF A LOOSE PART.

THE ALERT LEVEL AND ALERT LOGIC MAY BE REVISED TO PROVIDE FOR THE BACKGROUND NOISE OF THESE LATER MEASUREMENTS.

IF THE REVISION IS NOT TEMPORARY, ITS DETAILS SHOULD BE SUBMITTED WITHIN 60 DAYS TO THE COMMISSION AS AN AMENDMENT TO THE PROGRAM DESCRIPTION.

The RMS background noise level is

~

available on the f ront panel of each module for comparison with previous data.

In addition, time and frequency domain data evaluation using an oscilloscope and frequency analyzer may be made to more completely document and identify any change in the system perf ormance.

Note:

Per Reg. Guide 1.133, in the event this test results in a permanent system sensitivity adjustment, details of the change should be submitted to NRC.

(3)

COLD SHUTDOWN OR REFUELING:

AT LEAST ONCE PER 18 MONTHS, VERIFY CHANNEL L

. CALIBRATION USING A CONTROLLED MECHANICAL INPUT (E.G.,

WEIGHT FALLING THROUGH A KNOWN DISTANCE THAT IMPACTS THE EXTERNAL SURFACE OF THE REACTOR COOLANT PRESSURE BOUNDARY).

CHANNELS SHOULD, AS NECESSARY, BE RECALIBRATED AT THIS TIME.

IF RECALIBRATION IS NECESSARY, CONSIDERATION SHOULD BE GIVEN TO REPLACEMENT OF UNSTABLE COMPONENTS.

As per ST-2-036-408-1, channel calibration will be verified at least once per 18 months by use of a cor. trolled mechanical input.

no/10/19/83 Page 4 of 5

8 b -

4.

CONTENT'OF SAFETY ANALYS P ORT A DESCRIPTION OF THE LOOSE-PART DETECTION P ROGRAM SilOULD BE SUDMITTED TO THE COMMISSION IN RESPC::SE TO THE NRC STAFF REQUEST FOR INFORMATION ON LOOSE-PART DETECTION SYSTEM IN SECTION 4. 4. 6,

" INSTRUMENTATION REQUIREMENTS," OF REGULATORY GUIDE 1.70, " STANDARD FORMAT AND CONTENT OF SAFETY ANALYSIS REPORTS FOR NUCLEAR POWER PLANTS. "

THE PROGRAM DESCRIPTION SHOULD INCLUDE THOSE ITEMS COVERED IN REGULATORY POSITIONS 1, 2,

AND 3.

SPECIAL ATTENTION SHOULD BE GIVEN TO THE FOLLOWING ITEMS:

i)

PROCEDURES FOR MINIMIZING RADIATION EXPOSURE TO STATION PERSONNEL DURING MAINTENANCE, CALIB RAT ION, AND DIAGNOSTIC PROCEDURES.

- ( REFERENCE IN CHAPTER 12, "RADI ATIOti-PP4TECTidh3

• OF THE SAFETY _ A6MLYSLS REPORT lt is the pohey of PhMAelphh ElectVic, Company to maintain occupational radiation exposure ALARA at the Limerick Generating Station.

The company's commitment to this policy is manifested in established the' provisions for review of procedures, procedures and provisions for subsequent This includes procedures procedure revisions. calibration and diagnostic for maintenance, procedures for the LPMS.

s no/10/19/83 Page 5 of 5

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