ML20126K006

Provides Results of Evaluation of Stack Gas Monitor,Per 850315 Commitment.Location of Stack Gas Monitors No Obstacle to Operator Performance During Emergency Conditions.Minor Human Engineering Discrepancies Will Be Assessed & Resolved

ML20126K006
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	06/13/1985
From:	Kuemin J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8506190139
Download: ML20126K006 (6)

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Consumem Power Company General of fices: 1945 West Parnall Road, Jackson, MI 49201 . (5171 788 0650 June 13, 1985 Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT -

HUMAN FACTORS ANALYSIS OF THE STACK GAS MONITOR Consumers Power Company letter dated March 15, 1985 included a commitment to provide the results of our evaluation of the stack gas monitor, which was arde a condition of the Facility Operating License, section B(2)(e), with the approval of Amendment No. 70.

As noted in our letter of March 15, the analysis of the stack gas monitor was divided into two phases. The first phase consisted of a static human factors review of the stack gas monitor displays and controls, and was conducted as part of the Control Room Design Review. This phase included analysis of the readability of the add-on scale as required by the License condition. During the static phase of the analysis some human engineering discrepancies (HED) were identified relating to the meter, they will be discussed later.

The second phase of the human factors analysis of the stack gas monitor consisted of a dynamic evaluation of the ability to utilize the monitor during accident conditions to determine the acceptability of the placement of the meter other than on the main control panel. The monitor is located on the rear of the main panel. This evaluation was made during the recently completed Emergency Exercise on May 21, 1985. The results of this phase of the analysis will be discussed later also.

The Stack Gas Monitoring System provides continuous indication and record of stack releases of radioactive rases and iodine to the atmosphere under both normal and accident conditions. One of two plant exhuast fans must be operable for the monitoring system to provide a valid indication of release activity.

The stack gas monitor has two modes of operations the normal range and high range. Normal range noble gas and particulate and fodine activity are indicated on individual monitors and a dual recorder. At a stack release rate of approximately 100,000 pC1/sec the noble gas monitor activates the "High Stack Cao Radiation" annunciator on the front of the main control panel. At OC0685-0219-NLO4 A 5  %

Director, Nuclear Reactor Regulation 2 Big Rock Point Plant Human Factors Analysis June 13, 1985 this time also a grab sample is automatically taken for later analysis and the activity recorders switch to fast chart speed. The second mode of operation corresponds to when the Technical Specification limit of 0.47/E Ci/sec is reached. At this point, the "High-High Stack Gas Radiation" annunciator on the front of the main control panel is activated and a switch over to the high range noble gas monitor is automatically accomplished and the high range particulate and iodine filter changer are activated. The filters are monitored in the chemistry lab. The high range nobic gas indication is on an individual monitor and recorder separate from the normal range monitors and recorder.

The high range noble gas readings are used to determine atmospheric release rates. The Emergency Plan Implementing Procedures also include procedures for when the high range noble gas monitor is unavailable. For a radioactive release event inside containment where the radioactive release would not exit through the stack the release rate would be determined via offsite survey data. (The containment exhaust ventilation valves, two valves in series, which would allow release via the stack, close on all scrams, loss of air and/or power, and by a containment high radiation signal.) A radioactive release outside containment would likely involve a ground release as well as a release out the stack. For the release outside containment the plant ventilation system would direct the release, at least partially, to the stack.

The static human factors analysis of the stack gas monitor resulted in the Human Engineering Discrepancies (HED) listed below. The significance of these HED related to the readability of the monitor is considered minor. Although there will likely be some minor improvements made to the monitor, the add-on scale was judged to be easy to read during the static analysis.

HED Related to the Stack Cas Monitor A. Neither the iodine / particulate and noble gas recorder RR-8057 nor the high range noble gas recorder RR-8058 have units indicated.

B. The high range noble gas meter RI-8328 display units, on its red scale.

(original scale) are covered by the add-on scale.

C. The add-on scale for the high range noble gas meter has scale subdivisions which are in various multiples.

D. The original scales on the high range noble gas meter have no intermediate markings between the numbered markings.

E. Temporary add-on scales have been added to the normal and high range meters. The add-on scales are easy to read, however it is recommended they be redrawn and moved upwards so that increased information resolution can be obtained.

Oc0685-0219-NLO4

Director, Nuclear Reactor Regulation 3 Big Rock Point Plant Human Factors Analysis June 13, 1985 These HED will be assessed along with other HED that may result from the Control Room Design Review. Preliminary evaluations of the above HED are as follows:

The recorders noted in HED A duplicate their respective meter reading and have the same units of che maters. HED A will be resolved by adding the unit indications on the recorders.

HED B exists because the temporary add-on scales have covered the units for the original scale which are mR/hr. Although not completely unreadable, this HED will be rectified when HED C and E are resolved.

HED C is the result of adding a litear scale below the original semicircular scale on the meter. Equal divisions on the semicircular scale are unequal along the linear scale. A permanent scale to replace the add-on scale will be pursued with the vendor.

HED D is also considered to require no action. Because of the small scale size, additional indications on the scale which ranges 8 decades would not aid interpolation of the readings by an operator.

Resolution to HED E will be pursued with the vendor to provide a permanent scale to repince the add-on scale. However, as noted, the evaluator has indicated the add-on scale is easy to read.

The dynamic evaluation phase of the human factors analysis of the stack gas monitor was completed during the May 21, 1985 Emergency Exercise. A normal shift complement was used during the exercise. The purpose of this evaluation was to determine if an operator under pressure of accident conditions would or could take the time to walk behind the control panel and read the meter.

Ultimately this evaluation will determine if the noble gas atack monitors are satisfactorily situated or whether they should be moved. During the Emergency Exercise operators were required to obtain data from the monitor to analyze the release rate in order to provide protective action recommendations. The release rate data was provided to the participants at the location of the monitor on the back panel in units of the monitor readout.

The Emergency Plan Implementing Procedure for Operations Personnel contains instructions to fill out the Technical Support Center (TSC) data sheet at approximately 15 minute intervals. This data sheet (attached) has 14 readings for stack gas monitors, high range gamma monitor, core damage monitor, area monitors and process monitors. All these monitors are located in the same general location on the back of the main control panel. The stack gas readings are used in the TSC to determine off-site done release. Indication of high stack gas activity is annunciated on the front of the main control panel. The annunciator is a second method to trigger the operator to observe the stack gas activity.

OC0685-0219-N1.04

Director, Nuclear Reactor Regulation 4 Big Rock Point Plant Human Factors Analysis June 13, 1985 The results of the dynamic evaluation are:

Operations persor.nel took readings about every 15 minutes during the drill. The frequency was dependent on activities required in the drill scenario.

The operator appeared to have ample time to collect the information.

The average time for the 14 readings was about 3 minutes.

The location of the stack gas tonitor did not appear to have any negative effect on the collection of information to cope with the emergency (during the scenario).

The shift supervisors, control operators and on-call technical advisor were all asked during post drill questioning whether the location of the stack gas monitors posed a hindrance during the drill. All personnel indicated that the monitors location did not pose a hindrance.

We have concluded that the location of the stack gas monitors is no obstacle to the operator's performance during emergency conditions and they are adequate in their present location. Based on this conclusion the Consumers Power Company position is that the Facility Operating License section B(2)(e) has been satisfied. Further evaluation will continue as part of the Control Room Design Review Program and the minor Human Engineering Discrepancies discussed earlier will be nosessed and resolved.

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!JamesLKuemin Staff Licensing Engineer CC Administrator. Region III. USNRC NRC Resident Inspector - Big Rock Point Attachment OC0685-0219-NLO4

r ATTACIDiENT Consumers Power Company Big Rock Point Plant Docket 50 155 TSC DATA SIIEET June 13, 1985 1 Page IC0685-0219-NLO4

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TSC DATA SREET - BIG ROCK POINT PLANT Time Iog No Dnergency Classification Resetor: Radiological conditions:

a) Reactor Pressure (psis) al Stack Gas Monitor RI-8327 (com) b) Steam Drum Lvl from ( (inches) b) Hi Range Stack Mon RI-8328 ( :R/hr) c) Rx Water Above Core Yes O NoO c) Hi Range Gamma Mon RI-832h (R/hr) d) All Rods In Yes O nod (Core Damage) RI-8325 (R/hr) e) General Reactor Condition d) Area Monitores (mR/hr)

Spent Fuel Storaae No. 2 containment: Condensate Demin Entrance No. 8 Machine Shop Area No. 9 a) Containment Pressure (psis)

Turbine Shield Wall No. 17 b) Containment Water 14 vel (ft)

Radweste Vnit Entrance No. 18 c) MSIV Position her Condenser Vent-East No. 20 d) Ventilation Valves Position Dner Condenser kit-West No. 21 e) General Containment Condition Other Other Enaineered Safeauards: e) Process Monitordt (com) a) Emergency Condenser 14 vel (5) Radweste Discharge to Canal b) Bnerganey Condenser Temps Canal Discharge loop 1 (*F) Service Water Discharge to Canal Loop 2 ('F) General Plant Conditions:

c) Core Spray System Flow (spa) d) Backup Core Spray Sys Flow (aps) e) Containment Spray Sys Flow (spa) f) RDS Status Observations / Maintenance Statues g) Liquid Poison Status h) Steam Drum Relief Viv Status

1) Post Incident Recycle Yes O No O Operations Review Meterological Data: Radioloalcal Conditions:

a) Wind Direction (degrees from) a) TSC Dose Matos (mR/hr) b) Wind Speed (aph) b) TSC Airborne (pC1/ce) c) Sisma Theta (dearees) c) Core Damage Estimate (5) d) Pasquill Stability General Red Conditions /PAQ Recommendations:

Health Phystes Review Prosnosts: Stable O Escalating O De Escalatine O Terminatina O Potentint for Release YesO NoO Potential Release Duration (hours)

SED Reconunen$ations/ Actions Send To: _ 00CC _ EOF _ CSC SED Approval: Dates Distributtani White. Fan Creen-Cosesuntentor Canary. Tech Pink NP Collenroi. control Room