ML19290D917

Health Physics Survey - Air Sampling.

ML19290D917
Person / Time
Site:	North Anna
Issue date:	12/12/1979
From:	Hopper D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML19290D916	List: ML19290D915 ML19290D917 ML19290D918
References
RTR-NUREG-0578, RTR-NUREG-578 HP-3.3.2, NUDOCS 8002290383
Download: ML19290D917 (11)

Text

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[ i HP-3.3.2 Page 1 of 11 12-12-79 VIRGINIA ELECTRIC AND POWER COMPAH NORTH ANNA POWER STATION UNIT NCS. 1&2 HEALTH PHYSICS SURVEY - AIR SAMPLING 1.0 Purpose 2.0 References 3.0 Precautions and Limitations 4.0 Instructions e

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HP-3.3.2 Page 2 of 11 12-12 79

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HEALTH PHYSICS SURVEY - AIR SAtDLING 1.0 PURPOSE 1.1 This procedure ectablishes the equipment, techniques and cal-culations to be followed for air sampling.

2.0 REFERENCES

2.1 10CFR20 3.0 PRECAUTIONS AND LIMITATIONS 3.1 S.ir samples are to be obtained as scheduled in Procedure EP-3.3.1, Health Physics Survey - Station.

3.2 Air samples are to be taken as stated on current RWP's.

3.3 Sampling of ventilation ducts is described in Procedure HP-3.2.2, Radioactive Gaseous Waste Sampling and Release Rate.

3.4 Any area accessible to personnel with a beta gamma air con-

~9 centration in excess of 1 x 10 pCi/ml or alpha in excess of 1

~II x 10 is to be posted: CAUTION AIRE 0RNE RADI0 ACTIVITY AREA.

RWP REQUIRED FOR FJIRANCE.

3.5 In lieu of 3.4 above, if the concentration of the radionuclides present have been established, the ratios of the concentration to the MPC of each nuclide may be summed to determined if posting is required. If the sum is greater than one (1) or if individuals are expected to be in the area greater than 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> per week and the sum is greater than point two five (0.25) posting is required. (See 10CFR20.203(d).)

flP-3.3.2 Page 3 of 11 12-12-79 3.0 PRECAUTIONS AND LIMITATIONS (cont.)

3.6 Records of the results of all air samples taken to comply with this procedure shall be kept for the life of the station. The results may be entered on or attached to HP Survey Forms, or entered in the HP Log, or on separate sheets or forms for that pu rpos e.

4.0 INSTRUCTIONS 4.1 Noble Gases - Sampling 4.1.1 The following equipment is required.

1) 100 cc chamber with mylar window.

2) Hand aspirator bulb with short length of tubing attached (optional).

4.1.2 Obtain t'a e sample as follows: ,

1) Method One:

a) Remove the top of the chamber and wave the chamber in the atmosphere to be sampled.

b) Replace top securely.

2) Method Two:

a) Attach hand aspirating bulb to chamber and open both petcocks.

b) Purge chamber sufficiently (Adequate pu'6.ag of the collection chamber is acccmplished by drawing air through the collection chamber using the hand as-pirating bulb. Approxi=ately 10 as-pirations will provide a representative gas sample).

HP-3.3.2 Page 4 of 11 12-12-79 4.0 IhSTRUCTIONS (cont.)

c) Upon completion of purging close petcocks.

4.2 Particulates - Sampling 4.2.1 The following equipment is required:

1) Sampling pump with flow meter and sampling head atta ched.

2) 47 mm Gelman Type A/E filter or equivalent.

4.2.2 Obtain the sample as follows:

1) Install the filter in the sampling head.

2) Select an appropriate sampling flow rate and time interval to obtain sufficient sample for the activity sought.

NOTE: If radiciodine is to be sampled, the particulate filter frem that sample may be used in place of this sample. ,,

4.3 Radioiadine Sampling 4.3.1 The following equipment is required:

1) Sampling pump with flow meter and sampling head suitable for filter cartridge attached.

2) 47 cm Gelman Type A/E filter or equivalent and a Silver Zeolite cartridge or equivalent.

4.3.2 Obtain the sample as follows: ,

1) Install the filter in the sampling head with the Type A/E filter upstream of the filter cartridge.

2) Select an appropriate sampling flow rate and time interval to obtain sufficient sample for the activity sought.

HP-3.3.2 Page 5 of 11 12-12-79 4.0 INSTRUCTIONS (conr.)

4.4 Tritium Sampling 4.4.1 The followine eq'tipment is required:

1) MSA pot. ;e sampling pump or equivalent.

2) Midget i= pinger with 20 mls of demineralized water added.

3) Filter holder plus particulate filter.

4) Tubing to connect the above items.

4.4.2 Obtain the sample as follows:

1) Assemble sampling apparatus such that the filter is upstream of the impinger and the impinger is upstream of the pump.

2) Start pump and adjust flow to 2 scfh and sample

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for appropriate time interval.

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4.5 Subatmospheric Containment Sampling Considerations Air sample volumes to be determined using information obtained from a flow rate meter float under a vacuum (or pressure) other than standard pressure of 14.7 PSIA need the flow rate corrected before calculating the volume.

4.5.1 If the air sampler has a vacuum gauge attached correct the indicated flow rate to standard pressure flow rate:

1) Determine total PSLA of Containment sampled from the Control Room.

2) Note the inches of Mercury shown on the pump's vacuum gauge.

3) Calculate standard pressure flow rate by:

Indicated Flow s'

Flow Rate =

29.93 (2.036 x PSIA) - Pump Vacuum

2 EP-3.3.2 Page 6 of 11 12-12-79 4.0 INSTRUCTIONS (cont.)

4.5.2 If the air saspler does not have a vacuum gauge attached correct the indicated flow rate to standard pressure flow rate:

1) Determine total PSIA of Containment sampled from the Control Room.

2) Calculate standard pressure flow rate by:

Indicated flow Flow Rate: 14.7 PSIA 4.5.3 Flow rates referred to in calculating air sample activity in the procedure are to be the corrected flow rates.

4.5.4 When entering or exiting a containment with a closed 100 cc chamber rotate the petcocks periodically to prevent pressure damage to the mylar window. .

4.6 Constant Air Monitoring 4.6.1 To use a portable constant air monitor as an alert or alarm mor.itor for airborne particulate activity in a given area follow the steps below which are based on 2

~9 hours of exposure in any one day, ac MPC of 1 x 10 pCi/ml, a flow rate of I cfm and a counter efficiency o f 25* .

1) Install a clean filter in tie sampler. ,

2)' Set the alarm point at 2000 eps above background.

3) Start pump and adjust flow to I cfm. -

4) If no alarm has occurred at the end of two hours the filter say be replaced, or the alarm point may be reset as current cpm plus 2000, or leave the set point as is.

HP-3.3.2 Page 7 of 11 12-12-79 4.0 INSTRUCTIONS (cont.)

4.6.2 To use a constant air monitor to obtain continuous samples of airborne particulate activity, set up as follows:

1) Install a clean filter in the sampler.

2) Set the alarm point for MFC based on the antici-pated run time of the sample.

3) Start pump and set flow rate, noting the date, time and flow rate.

4) Remove filter at the end of the run, noting date, time and flow rate.

4.6.3 Emergency Iodine samples, using RadeCo He 809V-1 and Silver Zeolite cartridges.

( (1) Install a Silver Zeolite cartridge in the air sampler.

(2) Consider precautions when entering airborne areas, such as full anti "c's", SCBA, preset flow to air sampler and record flow rate.

(3) Go to the area of interest.

(4) Start H-809V-1. Note date, time and use pre-set flow rate.

(5) Leave the area until time has elapsed on sampler for approximately 1 SCF. -

(6) Return to area sampler, pick up the sampler and return to a " clean" area.

(7) Place the Silver Zeolite cartridge in a small plastic bag. Record flow rate, times, date and radiation reading.

HP-3.3.2 Page 8 of 11 12-12-79 4.0 INSTRUCTIONS (cont.)

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(a) If the radiation intensity is too high, precautions will have to be taken prior to counting, i.e. , changing the geometry.

NOTE: Silver Zeolite has a retention efficiency for Xenon of less than 5 x 10~ per cent.

4.6.4 Emergency Iodine sampling of process and ventilation vents, using in line samplers and Silver Zeolite cart-ridges.

(a) Replace the existing charcoal cartridges with a Silver Zeolite cartridge.

(b) Record the flow rate, time, date, etc.

(c) Leave the arma if high exposures are observed, natil the necessary flow rate has elapsed. A sample of approximately 1 SCF should be sufficient. -

(d) Return to in-line samp'ler and replace the used Silver Zeolite cartridge with another Silver Zeolite cartridge, again record time, date and flow rate.

(e) Place the used Silver Zeolite cartridge in a plastic bag with time, date, total flow rate and check with appropriate radiation detection instru-ment.

(f) If the radiation reading is above 1 mr/hr, take the necessary precautions prior to counting, i.e., change the geometry, shorter count time, etc. Make sure the ND 6650 is calibrated for a different geometry.

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HP-3.3.2 Page 9 of 11 4.0 INSTRUCTIONS (cont.)

4.7 Counting Air Samples 4.7.1 Noble Gases

1) Ensure the 100 cc chamber is free from removable external contamination or place in clean poly bag.

, 2) Count the sample for gamma emitters using a GeLi detector and Procedure HP-3.4.1.3. Mylar window is to be facing the detector.

3) Results are to be expressed as pCi/ml for each nuclide identified.

4.7.2 Particulates, Gross Beta-Gamma or Aloha

1) Use either the PC-4 or PC-5 Proportional counter and Procedure EP-3.4.1.2 or EP-3.4.1.5 respectively and count for activity sought in sample.

2) Calculate the pCi/ml by:

pCi _ , UCi of activity al - 2.83 x 10' x CFM flow rate x minutes sampled

3) Results are ;o be expressed as pCi/ml beta gamma or pCi/ml alpha.

4.7.3 Particulates - Gamma Isotopic

1) Place the filter paper in a poly bag or equivalent.

2) Count the sample for gamma emitters using a GeLi detector and Procedure HP-3.4.1.3.

3) Results are to be expressed as pCi/ml for each nuclide identified.

4.7.4 Radiciodine

\ 1) Place both filters in a poly bag or equivalent with filter next to the upstream face of the cartridge.

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• m g HP-3.3.2 Page 10 of 11 12-12-79 4.0 INSTRUCTIONS (cont.) T,

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2) Place the upstream face of the cartridge next to a GeLi Detector and count for gamma emitters per Procedure HP-3.4.1.3.

3) Results are to be expressed as pCi/ml for each radioiodine identified.

4.7.5 Tritium'

1) Transfer 3 mls of water from the impinger to a liquid scintillation counting vial and add 12 mis of scintillation solution. Shake to mix.

2) Count sample for tritium using the LS-100C and Procedure HP-3.4.1.1. This procedure will give pCi per sample.

3) Calculate pCi/ml by: ~T gCi = uCi per sample x 0.014 ml cfh flow rate x min. sampled 3

where 0.014 = 20 ml x 60 min. x 1 ft 3 ml hr 2.83 x 104 ml

4) Results are to be expressed as pC1/ml tritium.

s 4.8 Radon Daughter Interference

-8 Radon 222 has an MPC of 3 x 10 Ci/ml and is a common naturally occurring nuclide. It is a gas which has 10 dif-fet at radioactive particulate daughters which may or may not be in quilibrium with their parent. Radon or its daughters emit alpha, beta and gamma radiation and since Radon has' a higher MFC than the Station's MPC's for beta ga=ma or alpha, contribution from this source must be recognized and accounted for. Alpha airborne activity should normally not result from Station operctions.

HP-3.3.2 Page 11 of 11 12-12-79 4.0 INSTRUCTIONS (cont.)

4.8.1 Suspect Radon daughter activity if an air saaple indicates greater than 1 x 10'9 pCi/ml beta gamma and a possible source of airborne activity from Station operations is not apparent.

4.8.2 The following methods can be used, as appropriate, to indicate if the activity is from Radon 222.

1) Obtain another air sample in a different location which can reasonably be assumed to be free from airborne activity of Station origin. If results are similar, the activity is probably naturally occurring.

2) Count the sample for alpha activity, the presence s of alpha would indicate radon daughters.

3) Count the sample (for either alpha or beta gamma) at spaced time intervals. A decreasing activity would indicated radon daughters which will decay with approximately a 30 minute half-life due to Lead 214.

4) Take a high volume air sample and count for gama emitters to identify source.

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