ML20004E544

To Reg Guide 1.133, Loose-Part Detection Program for Primary Sys of Light Water Cooled Reactors

ML20004E544
Person / Time
Issue date:	05/31/1981
From:	NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
To:
References
TASK-OS, TASK-SC-523-4 REGGD-01.133, REGGD-1.133, NUDOCS 8106120320
Download: ML20004E544 (7)

Text

. _ _ _ _ _

Revision 1

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U.S. NUCLEAR REGULATORY COMMISSION my 1981 i REGULATORY G DE h\\ %j OFFICE OF NUCLEAR REGULATORY RESEARCH

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REGULATORY GUIDE 1.133 2 h

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N LOOSE-PART DETECTION PROGRAM SYSTEM OF LIGHT-WATER-COOLED REACTORS M. *,.

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l A. INTRODUCTION posed technical specifications relating to reperting neces-l sary to ensure operation of the facility in a safe manner.

Criterion I," Quality Standards and Records," of Appen-dix A, " General Design Critiera for Nuclear Power Plants,"

Paragraph 20.l(c) of 10 CFR Part 20, " Standards for to 10 CFR Part 50," Domestic Licensing of Production and Protection Against Radiatiop," states that, in addition to Utilization Facilities," requires that structures, systems, and complying with the requirements therein licensees should components important to safety be designed, fabricated, make every reasonable effort to maintain exposures to erected, and tested to quality standards commensurate with radiation as far below the limits specified in Part 20 as is the importance of the safety functions to be performed and reasonably achievable, thala quality assurance program be established and imple-j mented in order to provide adequate assurance that these This guide describes a method acceptable to the NRC structures, systems, and components will sausfactorily staff for implementing the above regulatory requirements perform their safety functions.

with respect to detecting a potentially safety-related loose part in light-water-cooled teactors during normal operation.

Criterion 13, " Instrumentation and Control," requires, This guide also outlines a program that can help licensees to in part, that instrumentation be provided to monitor meet the Part 20 criterion that exposures of station personnel variables and systems over their anticipated ranges for to radiation during routine operation of the station will (y

normal operation, for anticipated operational occurrences, be "as low as is reasonably achievable"( ALARA).

sad for accident conditions to ensure adequate safety,

\\ s)

(

including those variables and systems that can affect the The Advisory Committee on Reactor Safeguards has e

fission process, the integrity of the core, and the reactor been consulted concerning this guide and has concurred in coolant pressure boundary.

the regulatory position.

Section 50.36, " Technic specifications," of 10 CFR B. DISCUSSION Part 50 requires an applicant. )r a facility operating license to provide proposed technical specifications. Paragraph (cX2),

The presence of a loose (i.e., disengaged and drifting)

" Limiting Conditions for Operation," identifies a proposed part in the primary coolant system can be indicative of technical specification relating to the lowest functional degraded reactor safety resulting from failure or weakening capability or performance levels of equipment required for of a safety-related component. A loose part, whether it be safe operation of the facility. Paragraph (cX3)," Surveillance from a failed or weakened component or from an item Requirements," identifies a proposed technical specifica-inadvertently left in the primary system during construction, tion relating to test, calibration, or inspection to ensure refueling, or maintenance procedures, can contribute to that the riecessary quality of systems and components is component damage and material wear by frequent impacting maintained, that facility operation will be within the safety with other parts in the system. A loose part can pose a limits, and that the limiting conditions of operation will be serious threat of partial flow blockage with attendant met. Paragraph (c)(5), "AdministrativfControls," requires departure from nucleate boiling (DNB) which in turn could an applicant for a facility operating license to provide pro-result in failure of fuel cladding. In addition, a loose part increases the potential for control-rod jamming and for accumulation of increased levels of radioactive crud in the i in this guide the phrase loose part defection prTram encom-peases recommendatians ror system hardware and programmatic and primary system.

'oose-part defecston system refers only to reportins procutures.

e system hardware.

Lines indicate substantive chanses from September 1977 issa.

USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Commission, Wasnington, D.C. 2055 5, Regulatory Gulces are issued to describe and maine available to the Attention: Docket 6ng and Service Branch.

pu blic methods acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate tech-The guides are issued in the following ten broad divtstons:

f%

naques used by the staff in evaluating specific problems or postu-

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lated accidents or to provide guidance to appl 6 cants. Regulatory

1. Power Reactors

6. Products Guides are nol substitutes for regulations, and compliance with

2. Amearch and Test Reactors

7. Transportation g

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them es not required. Methods and solutions dif ferent from those set

3. Fuvs and Materials Fac614tles

8. Occupational Health out in the guldes will be acceptable if they provide a basis for the

4. Enyteanmental and Sit 6ng

9. Antitrust and FinanW Review findings requisite to the issuance or continuance of a permit or

5. Mater s',ed Plant Protection lo. General 14 cense by the Commission.

Copies of issueo Wides may be purchased at the current Government This guide was issued after considsration of comments received from Printing Of f 6ce pree. A subscription service for future guides in spe-the publ6c. Comments and suggestions for 6mprovements in these cif6c <Jtvisions is avaMie througn the Government Printing Offee.

information on the sutWr ntion w:We and current GPO prices may guides are encouraged at all times, and guides will be revised, as a

appropriate, to accommodate comments and to reflect new informa-be obtained by writing @a

..a. Nw er Regulatory Commission, tion or experience.

Washington, D.C. 20555, Attention h;blications Sales Manager.

l 8 ] 0 6 406e20

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Revision 1

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U.S. NUCLEAR REGULATORY COMMISSION ha y 1981 a

r 4

t@h,y REGULATORY G IDE OFFICE OF N" CLEAR REGULATORY RESEARCH

'N I

W

&9 REGULATORY GUIDE 1.133 j

D p%)s O

,-%m 1 FOR THE PRIMARYg-ej IF.-PART DETECTION PROGRAM SYSTEM OF LIGHT-WATER-COOLED REACTORS 4, *,.

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A. INTRODUCTION posed technical specifications re'ating to 'rt.

ing nices-sary to ensure operation of the facility in a safe manner.

Criterion 1," Quality Standards and Records," of Appen-dix A, " General Design Critiera for Nuclear Power Plants,"

Paragraph 20.l(c) of 10 CFR Part 20, " Standards for to 10 CFR Part 50," Domestic Licensing of Production and Protection Against Radiatiop," states that, in addition to Utilization Facilities," requires that structures, systems, and complying with the requirements therein licensees should components important to safety be designed, fabricated, make every reasonable effort to maintain exposures to crected, and tested to quality standards commensurate with radiation as far below the limits specified in Part 20 as is the importance of the safety functions to be performed and reasonably achievable.

that a quality assurance program be established and imple-mented in order to provide adequate assurance that these This guide d: scribes a method acceptable to the NRC structures, systems, and components will satisfactorily staff for implerr.enting the above regulatory requirements perform their safety functions.

with respect tc detecting a potentially safety-related loose part in light-water-cooled reactors during normal operation.

Criterion 13, " Instrumentation and Control," requires, This guide also outlines a program that can help licensees to in part, that instrumentation be provided to moniton meet the Part 20 criterion that exposures of station personnel variables and systems over their anticipated ranges for to radiation during routine operation of the station will normal operation, for anticipated operational occurrences, be "as low as is reasonably achievable"( ALARA).

and for accident conditions to ensure adequate safety, including those variables and systems that can affect the The Advisory Committee on Reactor Safeguards has e

fission process, the integrity of the core, and the reactor been consulted concerning this guide and has concurred in coolant pressure boundary.

the regulatco posit >on.

Section 50.36, "Technie Specifications," of 10 CFR B. DISCUSSION Part 50 requires an applicant. >r a facility operating license to provide proposed technical specifications. Paragraph (c)(2),

The presence of a loose (i.e., disengaged and drifting)

" Limiting Conditions for Operation," identifies a proposed part in the primary coolant system can be indicative of technical specification relating to the lowest functional degraded reactor safety resulting from failure er weakening capability or performance levels of equipment required for of a safety-related component. A loose part, whether it be safe operation of the facility. Paragraph (cX3)," Surveillance frores a failed or weakened component or from an item Requirements," identifies a proposed technical specifica-inadvertently left in the primary system during construction, tion relating to test, calibration, or inspection to ensure refuel'ng, or maintenance procedures, can contribute to that the necessary quality of systems and components is component damage and materialwear by frequentimpacting maintained, that facility operation will be within the safety with other parts in the system. A loose part can pose a limits, and that the limiting conditions of operation will be serious threat of partial flow blockage with attendant met. Paragraph (cXS), "AdministrativfControls," requires departure from nucleate toiling (DNB) which in turn could an applicant for a facility operating license to provide pro-result in failure of fuel cladding. In addition, a loose part increases the potential for control-rod jamming and for accumulation of increased levels of radioactive crud in the i in this guide the phrase loose-part derredon program encom-passes recommendations for system hardware and programmatic and primary system.

reporting procedures. Loo.se part derecdon system refers only to Lines indicate substantive changes from September 1977 lasue.

system hardware.

USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission.

U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, b

m th 5 accept bl t

R t

f I le nt g specific parts of the Commission's regulations, to defineate tech-The guides are issued in the following ten b oad divisions:

ofl ts u at r

1. Power Reactois

6. Products ated acc dent rt or vid u ance t the is n requir d ethods an of tions di ere ro ose e u sand t r als Fac I ties cupat on Health dings requis t t

sua eo c inua of a er to

. Ma r al a Pr tion Id. Gen 1

license by the Commission, l

This guide was issued after consideration of comments recalved from Pr t g Of a p ca.

su sc I tion rv6c fo u ure g ides n so the public. Comments and suggestions for improvements in these cific divisions is available through the Government Printin Office.

c mhants an to re t ee om ob at y

i ng t S N c ea R eg ato y omrr ss n,

poropr e, t ac omm a tion or experience.

Washington, D.C. 2o555, Attention Publications Sales Manager, e a oe aoso

9, The primary purpose of the loose-part detection pro' gram detection system senses that a predesignated alert levelhas is the early detection of loose metallic parts in the primary been reached or exceeded. An alarm alerts control room system. Early detection can provide the time required to personnel when the alert level is reached or exceeded. In avoid or mitigate safety-related damage to or malfunctions developing an automatic procedure for the continuous, of primary system components.

online detection of loose parts, some sensitivity will be sacrificed to minimize the potential for false alert signals.

The loose-part detection program also serves a second The manual data acquisition mode provides periodic moni-purpose since it can minimize radiation exposure to statica toring to detect loose parts, determine system operability personnel by providing for the early detection and general (including calibration), establish the alert level, and alert l

location of abnormal structural conditions. Information the licensee to data that require evaluation but are of from the program can be used by station personnel to focus insufficient magnitude or incorrect character to otherwise their efforts when taking remedial action to minimize the initiate automatic alert proceduies. Manual monitoring of formation of wear-generated radioactive c ud and to the audio portion of the sensor signals provides very high minimize the need for extensive structural repairs. The sensitivity to loose-part impacts with good capability for second purpose is consistent with the guidwe contained in recognizing spurious audio signals. Manual monitoring does, Rigulatory Goide 8.8, "Information Rel vant to Ensuring however, have the potential for increasing the burden on That Occupational Radiati n Exposures at Nuclear Power station personnel and should be used only on a periodic Stations Will Be As Low AJ !s Reasonably Achievable,"

basis.

which provides guidance. to licensees for maintaining occupational doses toindividuals as far below the permissible The loose-part detection prot, ram outlined herein is not limits specified in the NRC regulatios as is reasonably intended to be a research program. Instrumentation and achievable while, at the same time, providing guidance on procedures that will result in the need for disproportionate j methods to ensure that the sum of the doses received amount of attention by control room personnel are not1 by all exposed personnelis also at the lowest practicallevel, encouraged. Instrumentation that can be used to determine the approximate size and location of a loose part but The Advisory Committee on Reactor Safeguards (ACRS) that does not interfere with the normal alert and false signal d

and the NRC staff have, for the past vel years, been rejection function of the detection program would be encouraging applicants to employ online loose $ art detection usefulin complementing otherinstrumentation to determine systems in an attempt to stimulate technological devebpment the safety significance of a detected loose part. Loose parts in that area. This approach has resulted in a substantial traveling through the primary system will generally accumu-increase in industry-wide experience and confidence in late, at least for a time, in such natural collectior4 areas as these systems and has resulted in the commercial production the denums in reactor vessels and steam generators. There fore, of loose-part detection systems by several engineering and the NRC staff recommends that sensors be located at these manufacturing organizatiore. All applicants for a construc-and other natural collection areas. No oer.efit is seen in tion permit or an operating license are required to describe instrumenting straight lines of pipe or other areas through l

the loose-part detection program for the proposed reactor which a loose part will quickly pass F'ose scrutiny of a (Section 4.4.6," Instrumentation Requirements,"of Regula-relatively small amount of clearly '.<vant data is consid-tory Guide 1.70, " Standard Format and Content of Safety cred a better detection program tl.an cursory review of a Analysis Reports for Nuclear Power Plants").

large volume of less significant data.

An improperly developed and poorly implemented A prime consideration in developing the loose-part loose-part program may require excessive attention by plant detection program is the avoidance of procedures requiring opIrating personnel and more frequent inspections of the excessive attention by control room personnel and excessive primary system that can result in increased radiation reporting by the licensee. The re ommended program exposure. For this reason, this guide emphasizes the need would require operator action or engineering review when for providing system features that will minimize fake alert the detection methods indicate the p esence or possibility signals and for developing diagnostic procedures that can be of a loose part or whea performing pe-icdic audio monitor-quickly implemented to supplem:nt information from the ing or when confirming the operability of the instrumenta-loose-part detectic,n system to determine the short-and tion system. Licensee reports to the Commission during long-term safety signt2cance of aloose part. A well-developed operation are necessary when defining the alert level, loose-part detection syst:m should enable discrimination of when a loose part is confirmed to be present, or when the the signal induced by the inpact of a loose part from those associated technical specification is violated.

k sigaals induced by normi! hydraulic, mechanical, and electrical background noise and large amplitude electrical Although current loose-part detection systems can,in a l transients.

large number of cases, detect and indicate the approximate location and weight of a loose part, other information (e.g.,

The loose-part detection program outlined in this that obtained from plant process signals, from an inspection regulatory guide includes both automatic and manual of the facility, or from prior operating history) will be i

modes of data acquisition. These data acquisition modes necessary in most instances to determine the safety signif-provide for automatic and manual detection ofloose parts.

icance of the loose part. Therefore, no action with respect The automatic data acquisition mode provides for continuous to reactor operation is recommended based on the informa-monitoring of signals, but data are recorded only when the tion obtained from the loose-part detection system alone.

l 1.133-2 i

• e

An alert resulting from the loose-part detection system is react:rs during preoperational testing and ths startup end considered a warning, and it is important that followup pomfer operation mode = in accordance with the following steps (e.g., acquisition of additional diagnostic information) guidelines:

A' be taken to determine the significance of the alert signal.

(

j If a loose part is shown to be present,its short-and long-term

1. System Characteristics V

safety impli:ations need to be determined.

The following featwes should be incorporat' J into each The potential for damage initiated by a loose part is not loose-part detection system.

necessarily proportional to the impact energy of the loose part. For example, a small piece of flat metal plate may

a. Sensor Location. Sensors capable of detecting acoustic impart little impact energy but could restrict local flow to disturbances should be strategically located on the exterior the reactor core. However, there are technical difficulties in surface of the reactor coolant pressure boundary. A minimum trying to distinguish very-low-energy impact signals from of two sensors, suitably located to provide broad coverage, l the nortnal reactor acoustic background noise. Experience should be located at each natural collection region (e.g.,

with loose-part detection systems for operating pressurized reactor vessel upper and lower plenums and each pressurized-and boiling water reactorsprovides the basis for establishing water-reactor steam generator reactor coolantinlet plenum).

an impact energy of 0.5 ft-lb (0.68 joules), e.g., the kinetic energy of a 0.5-lb (0.23 kg) part traveling at 8 ft/sec (2.4 m/

b. System Sensitivity. The online sensitivity of the sec), as the recommended system sensitivity in Regulatory automatic detection system should be such that, as a l Position 1.b. Experience shows that signals resulting from minimum, the system can detect a metallic loose part that metallic-object impacts of that magnitude are distinguishable weighs from 0.25 lb (0.11 kg) to 30lb (13.6 kg) and from the normal background noise, and that, in some impacts with a kinetic energy of 0.5 ft-lb (0.68 joules) instances, even smaller impact energies are discernible at on the inside surface of the reactor coolant pressure bound-signal levels within background noise. levels when the ary within 3 feet (0.91 meter) of a sensor. If the recom-manual audio monitoring mode is being used, mended sensitivity cannot be achieved by automatic alert because of specifi,:in-plant conditions, these conditions and in order to ensure that, as a minimum, each loose-part the actual online sensitivity should be specified at the time detection system has the ability to detect what the staff the alert levelis provided (see Regulatory Position 3.a(2)(a)).

considers to be the most significant range of loose-part As an example, one acceptable method for verifying this weights, the staff recommends (Regulatory Position 1.b) online sensitivity is to demonstrate (1) the basic system that each loose-part detection system be capable of auto-sensitivity during plant shutdown and(2) that the background

/

matically detecting loose parts that weigh between 0.25 lb noise measured during normal plant operation is sufficiently

)

(0.11 kg) and 30 lb (13 6 kg) and impact with an energy of small that the signal associated with the specified detectable i

0.5 ft-lb (0.68 joules) or more. The specified weight range is loose-part impact would be clearly discernible in the considered to be representative of the most common and presence of this background noise.

significant class of loose parts. In addition, the staff recom-mends periodic audio monitoring by station per:onnel to

c. ChannelSeparation. The instrumentation channels complement the automatic detection system.

(e.g., cabling, amplifiers) associated with the two sensors recommended at each natural collection region should be The high radiation and thermal cycling environment to physically separated from each other starting at the sensor which most of the primary system is subjected could in locations to a point in the plant that is always accessible time alter operating characteristics of the loose-part detec-for maintenance during full-power operation.

tion system so that surveillance becomes ineffectual either by causing excessive alert signals or by decreasing sensitivity

d. Data Acquisition System. The system should include to loose parts. Therefore,in Regulatory Position I.f the staff both automatic and manual startup of data acquisition recommends that provisions be incorporated into the system equipment (see Regulatory Position 3). In the event the to permit channel operability (including calibration) tests, alett level is reached or exceeded, the data acquisition Regulatory Position 5 sddresses operability tests as part of a system should automatically activate, and an audible or surveillance requirement for a proposed technical specification.

visual alarm should alert the control room personnel of that condition. The data acquisition system should provide for Since an earthquake could induce a loose part in the the recording of all sensor signal waveforms in either analog primary system,it is desirable that the loose-part detection or digital form with the acceptability for selecting, as a system be designed to function following all seismic events minimum, any four sensors for simultaneous recording.

that do not require plant shutdown. Recording equipment, The system should be capable of immediate visual and however, need not be designed to function without main-audio moniscring of all signals.

tenance following such seismic events provided the system retains audio or visual alarm capability.

e. Alert Level. Provision should be made for incorporat-ing into the system an alert level that is indicative of the l C. REGULATORY POSITION presence of a loose part consistent with Regulatory Position

]

1.b. Depending on the alert logic (i.e., internal processing of

/

An eac ce loose-part detection program should be system signals), raw or processed signals should be auto-d

,U implerrented for the odmary system of light-water-cooled matically and continuously compared to the alert level.

f 1.133-3

l Points to be considered in establishing the aler,t level are The follov.ing points should be considered when estab-notedin Regulatory Position 2.

lishing the alert levels:

f. Capabilityfor Sensor Channel Operability Tests. Pro-

a. The alert logic should incorporate suitable internal vision should be made for periodic online channel check criteria to distinguish the transient signal caused by the and channel functional tests and for offline channel calibra-impact of a loose part from the signals associated with 2

tion during periods of cold shutdown or refueling (see normal hydraulic, mechanical, and electric noise and RIgulatory Position 3.a(3)).

large-amplitude electrical transients. For example,it may be desirable to include logic that requires the comparison of g.

@erability for Seismic and Environmental Conditions.

two or more sensor signals with the alert level.

Components of the loose-part detection system within containment should be designed and installed to perform

b. False alert signals resulting from plant maneuvers their function following all seismic events that do not (e.g., control-rod stepping, reactor trip, pump starts, and require plant shutdown,i.e.,up to and including the Operat-other known sources that cannot be avoided by the pro-ing Basis Earthquake (OBE). Recording equipment need cedures associated with Regulatory Position 2.a) may be not function without maintenance following the specified avoided by automatic procedures that momentarily override seismic event provided the audio or visual alarm capability the alert-level alarm. Alternatively, administrative proce-remains functional. The system should also be shown to be dures may be used by control room personnel in lieu of adequate by analysis, test, or combined analysis and test for automatic procedures to identify and make allowance for the normal operating radiation, vibration, temperature, and alert signals caused by plant maneuvers.

humidity environment.

c. The alert logic may provide for the alert level to be a

h. Quality o/ System Components. Components should function of the normal steady-state operating condition.

be of a quality thatis consistent with minimum maintenance requirements and low-failure rates. Components within the

d. As appropriate,it may be desirable for the alert logic containment should be compatible with the 40-year design to provide for the alert level to vary from sensor to sensor life of the reactor system. In those instances where a to compensate for the inherent *.evel of background noise at 40-year design life is not practicable,a replacement program a specific transducer location.

should be established for these parts that are anticipated to have limited service life.

3. Using the Data Acquisition Modes

1. System Repair. The system should be designed to The loose-part detection program should include data facilitate the recognition, location, replacement, repair, and acquisition in automatic and manual modes. 'the automatic adjustment of malfunctioning components. Equipment, mode is for continuous, online detection of loose parts. The procedures, and layout should facilitate maintenance manual mode is to be used periodically for detecting loose t2 minimize personnel time in high radiation areas and parts, de termining system operability (including calibration),

minimize occupational radiation exposure.

establishing the alert level, and detecting significant safety-related trends in the sensor signals and for diagnostic 1 Establishing the Alert Level purposes.

In all cases, the alert level should be consistent with

a. Manualmode. This mode of data acquisition should Regulatory Positions 1.b and I.e and should include the be used at the following times for the indicated purpose.

effects of background noise.

(1) Preoperational testing: Establish alert level for this test phase.

I The standard technical specifications define channel check.

(2) Startup and power operation.

channelfbnctional test, and channe! calibretton as follows:

A channel check is the qualitative assessment of channel behavior (a) Establish alert levels for startup and power during operation by obserystion, including, where possible, com-operation. The alert level for power 9peration should be taYderINd fro $"iNdNn*NnYi$truNnfc'ha nets meas r submitted to the Commissir,a (in the r2artup report when t

same parameter.

one is provided) within 00 days following completion of A channel /bactional test for analog channels is the injection of a the startup test program if the alert level is for power 88]",,$8,d,,8%i"8,, th* gy"'8 ** *8g,,g 'j,, n p f" c operation following initial startup or there is a change to th' T

s as Ior bistable channels the injection of a simulated signal into the preexisting alert levei for power operation. Temporary ghe el sensor to verify opernbuity, including alarm and trip changes to the alert level need not be reported.

A channel calibreffon is the ad ustment. as necessary, of the channel output so that it responds wi the necessary range and accuracy to (b) At least once per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s: Perform channel l known values of the parameter that the channel monitors. The

check, channel calibration encompasses the entire channel, including the sensor and alarm and trip functions, and includes the channel functional test. The channel calibration may be rformed by anY (c) At least once per 7 days: Listen to audio se o seg n apping, or total channe steps so that the I

1.133-4

f

' p Tose of Jetecting the presence of looss parts. If signals

a. Sergeor types, mounting locations, and mountint ladicate the presence or possibility of a loose part, station procedures, including criteria for choice of sensor and I

personnel should actuate the data acquisition system to mounting locations.

obtain data for further evaluation.

b. Data ncquisition, recording, and calibratior. equipment.

(d) At least once per 31 days: Perform channel functional tests.

c. Anticipated m4or sources of external and interri extraneous noise.

(e) At least once per 92 days: Verify that the background noise measured duringnormalplantoperationis

d. Precautions taken to ensure acquisition of quality sufficiently small that the signal associated with the specified data.

detectable loose-part impact would oe clearly discernible in the presence of this background noise. Verify that the signal

e. Description of the manner in which the alert level will I

from each recommended sensor does not falsely indicate be determined and also the alert logic (if any) employed by the presence of a loose part. This shouldinclude comparison the system hardware and software in generating an alert with data, including audio data, obtained at the time of the manal. This should include a description of the program last two quarterly measurements to verify that there does capability for disha843M between a loose part and not exist a significant trend or anomaly that may falsely normal background noise.

Indicate the presence of a loca part.The alertleveland alert logic may be revised to provide for the background noise of

f. Reference to the technical specification (see Rest.la-these later measurements. If the revision is not temporary, tory Position 5),

its details should be submitted within 60 days to the Com-mission as an amendment to the program description.

g. Summary of supplemental data and diagnetic procedures that are available and that can be used as pra of (3) Cold shutdown or refueling: At least once per a diagnostic program to confirm the presence of a loose 18 months, verify channel calibration using a controded part. The summary should address the use of information mechanical input (e.g., weight falling throash a known from plant process signals, radiation leakage monitors, distance that impacts the external surface of the reactor operating history, exercising of control rods, cycling of coolant pressure boundary). Channels should, as necessary, primary coolant pumps, and inspection of the primary be recalibrated at this time. If recalibration is necessary, coolant system.

consideration should be given to replacement of unstable

. components.

h. Procedures for performing channel check, channel functional test, and background noise measurements. l

b. Automatic mode. The automatic mode should be activated automatically when the predesignated alert levelis

i. Procedures for minimizing radiation exposure to exceeded. Activation sh6uld comprise an audible or visual station personnel during maintenance, calibration, and alarm to the control room operator and simultaneous initia-diagnostic procedures. (Reference in Chapter 12, " Radiation tion of data reccrding equipment. Data should be acquired Protection," of the Safety Analysis Report.)

for a sufficient period of time to properly characterize the signals from sensors suitably selected to provide maximum J. Traming program for plant personnel that addresses diagnostic information (e.g., the alarming sensor and several operation of the system hardware and the purpose and adjacent sensors may be selected). Each alert should be implementation of the loose-part detection program.

documented with regard to time and plant condition.

(Reference in Chapter 13, " Conduct of Operations," of the Safety Analysis Report.)

If the alert level is wxceeded or if the weekly audio monitoring or quarterly measurements indicate the presence

k. The applicant should verify that the system within or possibility of a loose prt, diagnostic steps should be containment will be designed and installed to function taken within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to determine whether a loose part is following all seismic events up to and including the OBE.

present and to determine its safety significance.

5. Technical Ser;ification for die imes Part Detection System

4. Content of Safety Analysis Reports A technical specification for ti.e loose-part detection A description of the loose-part detection program should system should be provided.- The technical specification be submitted to the Commission in response to the NRC should include:

staff request for information on loose-part detection systems in Section 4.4.6," Instrumentation Requirements," of Regu-

a. The locatio of the required sensors.

latory Guide 1.70, " Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants."

b. A limiting condition for operation requiring the loose-part detection system to be operable during startup The program description should include those items and power operation. If all channels of one or more collec-3 covered in Regulatory Positions 1,2, and 3. Special attention tion regions are inoperable for more than 30 days, the should be given to the following items:

reactor need not be shutdown, but a special report should 1.133-5

be prepared and obmitted 17 the Commission within with ths specified portions of th: Commission'a regulations, the next 10 days outlining the cause of the rha1 function the method described he cin will be used by the NRC staff and the plans for restoring the channel (s) to an operable in the evaluation of all construction permit applications and i

status, all operating license applications under review by the staff after January 1,1978.

c. A surveillance requirement that each channel of

, +

the loose-part detection system be demonstrated operable l by a channel check 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 />, For reactors licensed to operate prior to January 1,1978, a channel functicaal test performed at least once per loose-part detection systems that conform to commitments 31 days, and a calibration test performed at least once per of the license application should be installed and operable.

18 months.

The installation should be reviewed by the licensee to ensure that the quality of the installation and the calibra-

6. Notification of a Loose Part tion and use of the equipment are consistent with th:recom-mendations of this guide to the extent feasible for the loose-If the presence of a loose part is confirmed, the Commis-part detection system to which the licensee committed. The sion should be notified according % the guidelines for review should include an evaluation of the conformance to reportable occurrences that call for " prompt notification the appropriate programmatic aspects of the guide, specifi-with written followup" as summarized in Regulatory cally Sections C.2 and C.3, and whether specific hardware Guide 1.16," Reporting of Operating Information-Appendix or installation modifications are needed to make the systems A Technical Specifications."

effective for the detection of loose parts.

The followup report to be submitted to the Commission within 2 weeks of the initial notification of the presence of in cases where licensees of operating reactors (licensed a loose part should include (1) a summary of data obtained prior to January 1,1978) have not previously committed to in the manual sud automatic data acquisition modes;(2) a install a loose-part detection system or where the design of summary of the analysis, inspections, and correlations with an existing system precludes upgrading to an effective (perating data that were performed to evaluate data from functional capability, the licensee should install a system in the loose-part detection program; and (3)a summary of conformance with the programmatic aspects of the guide, conclusions and a description of modifications or other specifically Sections C.2 and C.3, or propose an acceptable actions planned or already performed to evaluate the safety alternative. In cases where a loose part is known to be implication of the loose part or to ensure that system and present or there exists a high probability that a part may crmponent safety functions are not impaired, become loose based on experience with other reactors of similar design, a loose-part detection system conforming to D. IMPLEMENTATION this guide should be installed.

The purpose of this section is to provide information to A letter will be sent to the licensee for each operating applicants regarding the NRC staff's plans for using this plant requesting that each licensee complete a review of his regulatory guide.

loose-part detection program and make any appropriate provisions for equipment and program revisions. Documenta-This guide reflects current NRC staff practice as outlined tion describing the results of this review and the resultant in Section 4.4 of the Standard Review Plan. The method loose-parts detection program should be prepared and presented in this guide has been recognized as acceptable available for inspection. It is the intent of the NRC to f r complying with the Commission's regulations since require that this effort, including the documentati o, be January 1,1978.

completed within 6 months after the effective issance date of this guide unless additional time is justified by the Therefore, except in those cases in which the applicant licensee in response to the NRC request to review the pr: poses an acceptable alternative method for complying loose-part detection program.

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