ML20071F428

Procedure HPA-63d, Calibr of Ventilation Sys Radiation Monitors

ML20071F428
Person / Time
Site:	Peach Bottom, Limerick, 05000000
Issue date:	05/16/1983
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML20071F431	List: ML20071F428 ML20071F446 ML20074B077 ML20074B081 ML20074B084
References
HPA-63D, NUDOCS 8305180438
Download: ML20071F428 (8)

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HPA- 63d P;go 1 cf 8 J!EILADEIMHIA ELECTRIC COMPANY PEACH BOTTON UNITS 2 6 3 HPA- 63d CALIBRATION OP VElffILATION SYSTEMS RADIATION MONITORS PURPOSE:

This test will demonstrate that the ventilation radiation monitor

• systems are operable, in calibration, have correct trip settings and '

perform specified annunciator functions on upscale and downscale trips.

REFERENCES:

Digital Ratemeter Manual, LFE Corporation, Bulletin 7610 - IN1 Low Level Radiogas Sampler / Detector Manual LPE Corporation, MQ-216 M-334 E-417 E-1674 Trapelo Drawing, D999280, M236-14 Trapello Dra w ing, B999274, M236-12 Technical Specificatio2 4.8.C.5 PREREQUISITES:

1. Approval of shif t supervision to perform the calibration.

2. Stable operating conditions or ass ociated Unit shutdown.

3. This procedure assumes that the equipment has been in operation and is ready for a routine check out and calibration.

APPARATUS:

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1. uci/cc Cylinders'ofcalibrationgas'(nominally of an appropriate certified standard such as10-1,Ig5),and10-5 Kr

2. Gas regulator with fittings to connect to gas sampler inlet.

PRECAUTIONS The power supply high voltage is hasardous to personnel. Normal pre-cautions should be taken when working on this equipment.

Contact plant Health-Physica for standard calibration gas and assistance before performing calibration.

8305180438 830516 hDRADOCK 05000352 PDR

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HPA-63d Page 2 of 8 THE OPERATION OF TWO CONTROL ROON VENTILATION RADIATION ALARNS, HIGH OR LOW, INITATES INTERRUPTION OF CONTROL ROOM VENTILATION. THEREFORE, CARE SHOULD BE TAKEN NOT TO TRIP BOTH UNITS SIMULTANEOUSLY.

l The following variables shuld not be exceeded: pressure greater than 3 psig or vacuum greater than 7" Hg in the gas sampler void volume to preclude damage to the sensor.

PROCEDURE:

The radiation monitoring system continuously monitors the radiation level of the air passing through the ducts. The control room monitor samples the supply air. All other monitors sample the system ventillation exhaust air.

, Each unit consists of a pumping system for drawing air samples from l the duct thru the gas sampler and filter holder. The gas sampler L

detector output is displayed on the digital rate meter as a count rate in cpm which is proportional to the concentration of gaseous activity pC1/cc in the sample. The sample to the filter holder is from an isokinetic sample line. The holder contains a filter disc for parti-culates and a charcoal filter or cartridge for iodines. The flow through

. the filters is regulated by an electro-pneumatic flow control valve located downstream from a control valve. This signal is fed to a square root extractor and then to a controller in the control room.

The controller positions the flow control valve to maintain a consrant flow rate. A flow alarm is also provided which will be activated by low vacuum (e.g., due to tripped sample pump). The pump discharge passes through a heat exchanger and back to the vent duct. No cooling water supply will be provided unless found to be necessary af ter operation.

The following components make up one system:

(1) Digital Ratementer DRM-100 (V-6) ,

(1) Low Level Radiogas Sampler / Detector MQ-216 (1) Roots Rotary Lobe Air Blower 1702J

! (1) Fischer & Porter Electronic Differential Pressure Transmitter (1) Fischer & Porter Electronic Square Root Extractor (1) Fischer Controls Electro-Pneumatic Transducer (1) Fischer Controls Diaphgram Actuator (1) Fischer Controls Valve

(2) Fixed Filter Holders (1) Heat Exchanger (1) Fischer'& Porter Electronic Controller (1) Rack OAC & OBC 186 (1) Control Panel 20C10 (1) Isokinetic Nozzle

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HPA 63d Pass 3 of 8 This description is applicable to the following systems

1. Control room ventilation supply two sample stations

2. Unit 2 roof vent two sample stations

3. Unit 3 roof vent two sample stations

4. Radwaste building exhaust one sample station

5. Recombiner building exhaust one sample station RADIOGAS DETECTOR

1. Eet the STATISTICS switch to 10% and the HIGH ALARM to 1.0 X 107 cym.

2. Verify Power on. The POWER light will be energised. The Nixie I

indicators will indicate any number, even multiple numbers if power had been off. Either or both the ALARM lights may be ON.

3. Turn the front panel switch to ALAIN REGET. The Alarm lights will go out.

4. Turn the internal Function switch to CIRCUIT RESET. The Nixie's will all reset to 0.

5. Turn the Fuction switch to TEST and hold it in that pogition.

Within 2 seconds, the display will change to 2.00 X 10 .

i 6. Immediately turn the switch to CIRCUIT RESET. ' Release it. Six seconds later, the display will change to 0.00 X 103. 54 secondg later (1 minute af ter releasing) the display will read 0.00 X 10'.

and the FAILURE alarm light will indicate.

7. Set the High Alarm switches to 1.0 X 10 6. Turn the function switch to TEST. The High Alarm light will indicate.

8. Set the STATISTICS switch to 3%. Repeat Step 5 above.

9. Immediately turn the function switch to CIRCUIT RESET. 4Release it.

Six seconds later, the display will change to 0.00 X 10 . 54 l

seconds later, the display will read 0.00 X 10 3.

10. Turn the circuit reset switch to the test position and hold for five seconds. Release the switch to the OPERATE position. Six seconds later the display should indicate some random number X 104 .

11. Reset the STATISTICS switch to 10% and repeat step 10. The display should indicate some random number X 103 .

12. The controls may be now set to the proper operating positions.

Refer to Table HPA-3.c l. .

LOW LEVEL DETECTOR CALIBRATION PROCEDURE

13. Turn the ratemeter high voltage control to 000, turn on ratemeter and ratemeter high voltage, set threshold control to 200.

14. Turn Function switch to TEST position and observe 2 X 106 CPN display.

15. Turn Function switch to CIRCUIT RESET position and observe 0.00 X 100 CPM display.

16. Energize check source and increase high voltage until ratemeter starts to count. N'te o cpm at discrete voltage settings.

DO NOT EXCEED 1600 VOLTS

17. Plot high voltage vs. count rate until.a plateau is observed.

18. De-energize check source and plot high voltage vs. background.

DO NOT EXCEED 1600 VOLTS

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HPA 63d Page 4 of 8

, 19. Set high voltage at point where check source reading is on plateau and background is between 80 and 90 CPM. Lock in high voltage Control.

. 20. Set threshold control at 600, energize check source and record racemeter readir.3 on data sheet HPA-3.c.1.

21. De-energise check source, set threshold control at 200. Ratemeter is now set-up for sensitivity testing. l

22. Operate sample purge switch.

23. Shut off sample pump. Roset sample purge switch.

24. Close gas sampler inlet valve.

. 25. Verify gas sampler discharge path is open.

26. Connect standard gas cylinder to gas sampler inlet lina.

27. Record bacground reading on digital rate agter and recorder.

28. Inject Kr at a known concentration ( 10~ pC1/cc) into the sampler at a slow rate. Purge for 5 to 15 seconds, then close off tiu standard gas supply to the gas sampler by closing the valve between the gas cylinder regulator and the gas sampler inlet line. Continue this interrupted purge until the count rate has come to equili-brium (5 displays that show no change in count rate except for statistical variation). Secure the gas supply and then close the gas sampler outlet valve. Care should be taken to close the supply valve first. Do not pressurise the system. Continue to observe the ratemeter count rate and observe that there is no change in count rate (except statistical). If there is a change in count rate, equilibrium was not achieved while the gas was flowing.

Repeat the interrupted flow until there is no change in five successive count races. Record count rate on data sheet MPA-3.c.1 and establish low level calibration point on los graph paper.

29. Inject Kr 85 at other known concentrations (e.g. nominally 10~3 pCi/cc and 10*1 pCi/cc) and repeat the procedure followed in step 28. Record the count rate on data sheet HPA-3.c.l. At least two calibration points shall be obtained.

30. Subtract the background cym from cpm corresponding to each cali-bration point.

31. Plot a curve of not cpm vs pCi/cc on los los paper.

32. Purge sampler with clean air to a stable background reading.

33. Energize the Sr-90 check source. Record the reading on data sheet HPA-3.c.l. Compare the check source reading with previous check source readings. Reading shall be within + 20% of original value corrected for decay.

34. DeterminethenotcpmperpC1/ccfromthe9urve.

35. Determine the cpm corresponding to 1 X 10~ pC1/cc.

.36. Calcu?. ate the o of a series of background readings as follows:

a) operate the sample purge switch b) observe and record 5 to 10 background readings (each reading will be for one minute) on data sheet HPA-3.c.2.

c) average the background readings and take the square root of

! this average. This is o of the background.

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37. Multiply the o of background from step 36 by 2.56.. '

38. ' Compare.this;value with the cpu corresponding to 1 X 10-7'bCi/cc.

The cpm value corresponding to 1 X 10-7 pCi/cc shall be greater-than 2.56 o of the. background.

39. Supply copies of.the es11bration curve to the surveillance test supervisor and post copies'in the control roce.

UPSCALE AND DOWNSCALE TRIPS.

40. : Turn ANALOG OUTPUT switch to 8 10 position (normal position is 104 ).

41. Set H.H. alarm pot to full clockwise and reset any alarms.  ;

. 4 2. - Turn TEST switch to TEST and hold. Rataseter read out will'be l 2.00 X 10 . . Rotate Hi Hi alarm pot counter clockwise. The Hi Hi-alarm should trip at a pot position of'7.55 i .10. Record observa-tions.

' 43. Release TRST switch and' turn it to CIRCUIT RESET.

'44. Turn off high voltage. Downscale alarm should trip in about 1 to 2  ;

. minutes. Record observations.

45. High and High High alarm trips may be checked by a) operating the check source with the high and high high alarm settings equal to or less than the current check source reading.

(corrected for decay), or b) substituting the detector output (turn off H.V. then disconnect detector cable at drawer) for a variable pulser output (use jack in back of drawer).

46. Record observations.

47. Verify that the red and black pens on recorders track within i 1.52 ELFS their respective indicator and-tsip units.

ELFS MEANS EQUIVALENT LINEAR FULL SCALI.

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.48. Return system to normal. - Notify shift supervision.

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TABLE HPA-63.d.1 RANGE HI ALARN HI HI AIGH STATISTICS SWITCH THUNR WHEEL POT S FFtING THRESHOLD 1 unid 2 unita 1 unit 2 units 6

Control Room A 10X 10 200 Setpoints to be determined 6

B 10X 10 by HP G C and posted in 200 the area of the vent, Radwest* 10% 10 6 2@

radiation monitors.

0 Recombiner 10X 10 200 Unit 2 Roof Vent A 10X 106 200 0

3 10X 10 200 6

Unit 3 Roof Vent A 102 10 200 5 10X 10 0 200 1

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