ML20137Z729
| ML20137Z729 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 09/12/1985 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| FVY-85-86, NUDOCS 8510080352 | |
| Download: ML20137Z729 (24) | |
Text
6.
s 3
VERMONT YANKEE-NUCLEAR POWER CORPORATION FVY 85-86 RD 5. Box 169. Ferry Road. Brattleboro. VT 05301 y,go
, p ENGINEERING OFFICE N
1671 WORCESTER ROAD FRAMINGH AM, MASS ACHuSETTS 01701 TELEPHONE 617 672-6100 September 12, 1985 U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attn:
Mr. Thomas T. Martin, Director Division of Radiation Safety and Safeguards
References:
a)
License No. DPR-28 (Docket No. 50-271) b)
Letter, USNRC to VYNPC, NVY 85-109, Inspection Report No. 85-13, dated 5/30/85 Attachments:
1)
Memo, S.P. Skibniowsky to Department Heads, Emergency Response Training-1985, dated June 20, 1985 2)
Memo, F.J. Darois to G.D. Weyman, Evaluation of Survey Meters in a Plume Environment, dated March 14, 1984
Dear Sir:
Subject:
July 3, 1985 Meeting at NRC Region I Concerning the 1985 Vermont Yankee Emergency Exercise A meeting was held on July 3, 1985 at the NRC Region I office to discuss three areas of concern that were identified during Vermont Yankee's 1985 Annual Emergency Exercise. These areas include:
1.
Overall direction and control of emergency activities.
2.
Delineation of responsibilities of key managers in the Emergency Plan.
3.
Communication flow and dissemination of information between emergency facilities.
The specific requests made by your staff and our responses to them tre as follows:
1.
Evaluate the authority and functional responsibility of key managers in the Emergency Plan.
RESPONSE: Vermont Yankee will perform this evaluation and incorporate all changes in the plan prior to the next annual exercise.
U 8510080352 850912 PDR ADOCK 05000271 F
)
o VERMONT YAN.4EE NUCIEAR POWER COMPORATION U.S. Nuclear Regulatory Commission September 12, 1985 Page 2 2.
Modify the training of key managers in any changes or revisions noted in Item 1).
RESPONSE
Training will be performed for all key managers on changes to the plan prior to the next annual exercise.
3.
Assess the overall system of data collection and dissemination of infor-mation between emergency response facilities.
RESPONSE: New status forms, status boards and transmittal methods have been instituted and will be tested and evaluated before the new EOF is declared operational. Hardware changes such as MET data lines / printer and VAX computer terminals are scheduled to be completed prior to December 1987.
Implementation of SPDS is proceeding in accordance with the schedule negotiated with NRR.
4.
Review the frequency of conducting drills in the functional areas of com-munication, dose assessment, health physics, medical and practice exer-Cises.
RESPONSE: An emergency response exercise and drill program has been established procedurally and numerous mini-drills are conducted as part of the Emergency Plan training of personnel (Attachment 1).
These do not include the Chem /HP department's individual HP trainig and computer dose assessment training which is performed on a semi-annual basis.
5.
Conduct a drill to evaluate the changes made from the items identified above.
RESPONSE: A drill was held September 11, 1985, to evaluate Item 3.
The 1986 annual exercise will test Items 1 and 2 if changes are deer.ed necessary.
Additionally, in accordance with Reference b), NRC inspectors identified an open item (50-271/85-13/24) which states that off-site monitoring procedures do not require open/ closed window measurements of survey instruments to assist in determining the presence of the plume.
During this meeting, we expressed our position that there is no technical reason for performing open/ closed window measurements to determine the presence of the plume. This was based on Yankee Atomic Nuclear Services Division per-forming an evaluation concerning this open item.
Enclosed is a copy of this evaluation (Attachment 2) for your review as requested by Mr. James Hawxhurst of your agency.
1
VERMONT YANKEE NUCLEAR POWER CORPORATION U.S. Nuclear Regulatory Commission September 12, 1985 Page 3 We trust this response addresses your concerns.
If you require any further information, please contact us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION W
W Warren P. Murphy Vice President and Manager of Operatio
/dm
- cc: Atomic Safety and Licensing Board Service List Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 4
4 s.
ATTACHMENT 1
.__?
MEMORAN M TO Dept. Heads Vernon + Brattleboro June 20,1985 Location DATE FROM S. P. Skibniowsky Vernon FILE 17.1 Location JUN27 g SUBJECT Emergency Response Training - 1985 The following schedule is provided to meet the requirements of Emergency Response Training for 1985:
I Category I - General Plant Staff - 0800-1200 Classroom D 1
-i July 9 July 10 July 16 July 17 D. Cobb J. (Kowalski) Smith S. Lyon P. Dean P. Thayer T. Carey G. Vitello C. Porrovecchio G. Gilmore Ron Page Sr.
S. Mcriarity W. Blanchard R. Merrigan H. Lewis J. Babbitt R. Putnam C. Faulkner T. Purinton J. Mulligan C. Monmaney C. Hmphrey J. Arensmeyer R. Selly N. Paust J. Halvey N. Levesque D. Knechtly S. Jenkins M. Robert S. Wender H. Heilman D. Stafford D. Hopta T. Watson W. Finnell L. Sprague J. Sullivan J. Golonka H. Atkins D. Taylor H. Boguslawski G. Faulkner A. Jackson C. Parant M. Yeaw L. Wright T. Bush D. Niedzweickt W. Casey L. Chapin E. Conkey R. Sak N. Prokowich T. Guerriere W. Gouin W. McKinnon R. St. Pierre E. Matson C. Rose W. Christmas R. Sharpe D. Jarvis W. Gardner D. Metevier A. Gaspardino H. Fortin L. Jenks J. Graves
~. Sicard R. Mossey J. Kellom P
1 J. Green i
E. Massey D. Hallonquist G. Wallin S. Orlando W. Fields D. Leyere K. Sherk G. Shea T. Stetson J. Brooks D. Bauer D. Allen D. Girroir F. Burger G. Cappuccio D. McElwee p
1 J. Walsh M. Metell D. Phillips T. Trask J. Hmphries J. Dellincentis C. Lohmeyer P. Corbett L. Boisvert R. Stickley
MEMORANDUM Page two Category II - Emergency Response Teams - OSC - Classroom D July 24 0800-1130 July 241230-1600 J. Sullivan W. Finnell D. Taylor H. Boguslawski G. Faulkner H. Atkins C. Parant M. Yeaw L. Wright A. Jackson D. Neidzwiecki
. W. Casey L. Chapin T. Bush R. Sak N. Prokowich "
T. Guerriere E. Conkey W. McKinnon R. St. Pierre E. Matson W. Gouin W. Christmas R. Sharpe D. Jarvis C. Rose D. Metevier A. Gaspardino J. Arensmeyer R. Selby N. Paust J. Halvey N. Levesque D. Knechtly S. Jenkins M. Robert S. wender D. Stafford D. Hopta C. Lohmeyer R. Stickley Category II - Emergency Response Teams - OSC - Mini Drill Auo. 2 - 0800 Aug. 2 - 1230 Aug. 9 - 0800 Aug. 9 - 1230 J. Sullivan W. Finnell D. Taylor H. Boguslawski
}^.
G. Faulkner H. Atkins C. Parant M. Yeaw
.y L. Wright A. Jackson D. Neidzwiecki W. Casey L. Chapin T. Bush R. Sak N. Prokowich j
T. Guerriere E. Conkey W. McKinnon R. St. Pierre A
E. Matson W. Gouin W. Christmas R. Sharpe D. Jarvis C. Rose D. Metevier A. Gaspardino J. Arensmeyer R. Selby N. Paust J. Halvey N. Levesque D. Knechtly S. Jenkins M. Robert S. Wender D. Stafford D. Hopta C. Lohmeyer R. Stickley R. Branch W. Lindquist B. Metcalf P. Klaski G. LeClair H. Sutton D. Porter J. Herron D. Labarge
C.
MEMORANDt.H Category III - Emergency Response Teams - EOFAC - Classroom D August 19 - 0800-1200 August 19 - 1200-1600 G. Wallin T. Stetson J. Brooks G. Shea K. Sherk D. Allen D. Girroir D. McElwee F. Burger J. Walsh D. Bauer M. Metell D. Phillips G. Cappuccio T. Trask J. Hmphries J. DeVincentis P. Corbett
- i L. Boisvert E. Massey i
R. Mossey D. Hallonquist S. Orlando W. Fields D. Legere L. Sprague J. Golonka G. Humphrey T. Watson H. Heilman D. Cobb, J. -(Kowalski) Smith J. Babbitt S. Lyon R. Putnam G. Faulkner G. Porrovecchio T. Purinton G. Gilmore Ron Page Sr.
S. Moriarty W. Blanchard R. Merrigan D. Lyon H. Lewis J. Mulligan Category III - Emergency Resoonse Teams - EOFAC - Mini Drill August 27 - 1200-1600 Auoust 29 - 1200-1600 1. Wallin T. Stetson J. Brooks G. Shea K. Sherk D. Allen D. Girroir D. McElwee F. Burger J. Walsh D. Bauer M. Metell A
D. Phillips G. Cappuccic k
T. Trask J. Humphries 4
J. DeVincentis P. Corbett L. Boisvert E. Massey R. Mossey D. Halonquist 1
Sect. 3 - 1200-1600 Sept. 4 - 1200-1600 S. Orlando W. Fields D. Legere L. Sprague J. Golonka C. Hmphrey T. Watson H. Hellman D. Cobb J. (Kowalski) Smith J. Babbitt S. Lyon R. Putnam C. Faulkner C. Porrovecchio T. Purinton G. Gilmore Ron Page Sr.
S. Moriarty W. Blanchard R. Merrigan D. Lyon H. Lewis J. Mulligan
I.,..
MEMORANDUM Page four Category IV - TSC/OSC Coordinators - Classroom D
~
July 22 - 08CO-1400 August 5 - 0800-1400
[
J. Pelletier D. Reid B. Wanczyk R. Lopriore P. Donnelly B. Leach J. Desilets B. Buteau R. Pagodin S. Jefferson R. Branch G. LeClair P. Klaski B. Metcalf W. Lindquist D. Porter H. Sutton J. Herron D. Labarge Category IV - TSC/OSC Coordinators - Mini Drill Aucust 8 - 1230-1600 J. Pelletier D. Reid B. Wanczyk R. Lopriore P. Donnelly
- 8. Leach J. Desilets B. Buteau R. Pagodin S. Jefferson
)
R. Branch G. LeClair d
D. Labarge I
e
r-MEMORANDUM Page five Category V EOF Coordinators - Classroom D July 23, 0800-1600 July 30 0800-1600 J. Pelletier D. Reid B. Wanczyk J. Desilets R. Pagodin B. Buteau R. Branch P. Donnelly R. Lopriore G. LeClair B. Leach S. Jefferson Category V - EOF Coordinators - EOF Mini Drill 1200-1600 Aug. 27 Aug. 29 Sept. 3 Sept. 4 8
)
J. Pelletier D. Reid R. Wanczyk R. Pagodin J. Desilets B. Buteau R. Branch P. Donnelly R. Lopriore G. LeClair B. Leach S. Jefferson Category VI - Site Recovery Manager + Staff - Classroom D July 29 - 1300-1600 W. Murphy R. Lodwick
.W. Penniman T. White W. Anson R. Milligan and others
^
jlpjj Category VI - Site Recovery Manager - Mini Drill August 26 - 1300-1600 hf W. Murphy R. Lodwick W. Penniman T. white W. Anson R. Milligan and others
e.
MEMORANDtN Page six Category VII - Chem + H.P. Technicians - Classroom 0 2 day sessions (12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />)
July 31 + Aug 1 Aug. 6 + 7 Aug. 20, 21 D. Truesdell S. Berger R. Warriner P. Manley D. Ervin E. Miller S. McAvoy R. Gerdus D. Tkatch D. Holmquist D. Bruce Category VIII - Ches + H.P. Radiological Assistants - Classroom D 2 day sessions (12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />)
July 18 + 19 July 25, 26 3
T. McCarthy M. Prystupa R. Morrissette E. Keegan J. Gardner P. Polaski R. Hurst M. Fuller E. Porter L. Savard D. Tolin Category VIII Chem + H.P. Radioloolcal Assistants - Mini-Drill - EOF /RC 1
Aug 27 Aug 29 Sept 3 Sept 4 T. icCarthy M. Prystupa R. Morrissette E. Keegan J. Gardner P. Polaski F. Hurst M. Fuller E. Porter L. Savard D. Talin h
Category IX - Main Office Staff (Switchboard Operators) - Main Office iv
)
August 23 - 1300-1500 17..
S. Lyon D. Cobb P. Dean P. Thayer B. Vitello T. Corey C. Momaney and others
n-MEMORANDlN
+
Page seven All training sessions are conducted in areas as specified. All Mini Drills are conducted on location in the applicable Emergency Response Facility.
If you have any questions concerning this schedule, please contact me at your earliest convenience.
i k
0 i
}..
21 i
cc - Dept. Clerks B. Pritchard J. Golonka G. Wallin R. Mossey E. Massey 4
)
ATTACHMENT 2 tenwan IO n_ wavman March 14.1984 Location Date Faa4 ri narn5<
FILE No.
Et 88/84 Location SURJECT_ENAlllATTON OF 911RVFY MFTFRS TN A Pi tlMF FNVTRONMFNT I.
REFERENCES
~
3 1.
Memo from R. W. Burke to L. D. Marsolais; Service Request - Survey J
Instrumentation Response, June 24, 1983.
}l 2.
Memo from A. D. Hodgdon to E. L. Darois; Accident Plume Meter -
j Calculated Gamma and Beta Average Energies for Fission Noble Gasesc REG
.i 173/83, September 20, 1983.
1 3.
SKIRON-II "A Computer Code for the Determination of Atmospheric Dispersion Factors for Potential Accident Consequence Assessments at Nuclear Power Plants", ENTECH Engineering Inc., P100-R7; by John H.
Hamawi, Phd, Dec 1981.
II.
INTRODUCTION In the event of an Emergency at Vermont Yankee resulting in a release of radioactive material to the environment, of f-site Radiological Monitoring Teams (RMT) are dispatched to prescribed locations within the plume. Their function is twofold; (1) to measure the whole body gamma dose rate, and (2) to measure the airborne concentration of Halogens and particulates via air sampling. Since the results of these measurements are crucial in prescribing Protective Action Recommendations to the public, then any method which could accelerate the measurements should be employed. The most time consuming item is the air sampling process since a 10 to 15 minute air sample is required.
If the RMT can determine that their location is not within the plume prior to air sampling, then the air sample may be omitted, therefore, eliminating at least 15 minutes.
- )
One possible method of determining the presence of the plume would be by observing the' ratio of open-to-close window survey meter response.
If this r; -
ratio is greater than unity by some pre-determined f raction, then beta e
radiation is present as is the plume.
Prior to implementing this technique, its sensitivity must be evaluated to determine its feasibility. Reference 1 d'
requested that this evaluation be performed for three survey meters; the PIC-6A, the E-520, and the PRM-4.
This memo presents the results of this evaluation and provides the appropriate recommendations.
e
J D. Weyman March 14, 1984 Page 2 III. METHODS A.
Calculated Beta to Gamma Dose Ratios Prior to evaluating the survey meters, a range of anticipated beta to gama dose ratios in a plume environment to needed. This is done by first considering the method of calculation of each 1
separately. The gama dose rate, Dy, and beta dose rate, Dg, is given as follows:
i I
f U}
D (mRemhr-I) = 0(uci sec
)
X/0h sec m )
fy(t) mRemhr )
D (mRemhr-I) = 0(uci sec
)
(sec m N,
W B
fB(t) mRemhr )
Where; Q(pCi sec-I)
= the total activity release rate, X/Q (see m-3)
= the finite cloud gamma diffusion factor, T
X/Q (sec m-3)
= the concentration atmospheric diffusion C
- factor,
"_3
= the whole body gama dose conversion Y
f (t) mRemhr )
factor for the fission product mixture at t hours after shutdown, and
"_3
=thebetaskigdoseconversionfactor 0
f (t) mRemhr )
at 7 mg cm tissue depth for the 9
fission product mixture at t hours af ter shutdown.
l From equations 1 and 2, the ratio of beta to gama dose rates is a
]
given below in Equation 3.
D C0 X/0 f (t) 8
=
D Y Y y
X/Q f (t)
The gamma diffusion factor is a function of gama energy which is dependent upon time after shutdown of the fission product mixture.
Therefore, this parameter must be evaluated at the same decay times 0
as the dose conversion factors f (t) and fY(t)). Also, values of both the gama and concentration dif fusion factors must be evaluated for dif ferent plume geometries (i.e., stability class and downwind distance).
t i
D.' Weyman March 14,1984 Page 3 From Reference 3, values of the gamma and concentration diffusion 4
factors were evaluated for stability classes A, C, and F at i
4 distances of 0.5, 2, and 10 miles f rom the plant for a ground level release at plume centerline locations. The gamma diffusion factors were determined for a range of average gamma energies for
(
the noble gas fission product mixture from 0.7 to.05 MeV. This i,
range corresponds to decay times of 0 to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> respectively as D
determined by Reference 2.
A ground level release and plume j
centerline receptor location conditions were chosen since this 9
represents the largest possible values of beta to gamma dose 3
ratios.
d Table 1 shows the ratio of gamma to concentration diffusion factors for the conditions described above.
0 Values of the dose conversion factors (f (t) and fY(t)) were L
also determined from Reference 2 for the noble gas component of the fission product mixture f rom 0 to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> after shutdown
(
These values, along with.the ratio of fgecaytime).
(t) and fY(t) are provide <' a Table 2.
From Table 1, the minimum and maximum diffusion factor ratios were determined for each decay time and used in conjunction with the dose conversion factor ratios, as given in Equation 3, to determine the minimum and maximum gamma to beta dose ratios for each decay time.
This data is given in Table 3.
From these values it is seen that the maximum and minimum gamma to beta dose ratios are 1.91 and.196, respectively. For the purpose of the survey meter evaluation, two additional intermediate ratios will values will also be employed. Therefore, the following Dg/07 i
used for the evaluation; 1.91, 0.82, 0.41, and 0.196.
The actual survey meter response for the open window condition
[
must be compared to the gamma plus beta dose rate or the shallow dose rate, denoted as Ds where; n-I (4)
Dy + Dg Ds
=
Therefore, for direct comparison, the above values for Dg/D y are converted to D /D by the following relationship; s y D
D (5) 3 g
D I+D Y
Y l
Using Equation 5 above, the above ratios of Dg/Dy are converted to the following values of D /D respectively, 1.52, S y j
2.22, 3.43, and 6.10.
These values will be used as comparison to the open-to-close window survey meter response, R /Rc-o e
Dm-yv.---
,.v.-
,7--,.,y,- -
--w.y,,
y,,9
,.p,
,.w,.m,m p..,
,y 7,
.n
.__,y 7
p
r D. Weyman March 14, 1984 Page 4 The last parameter which must be considered in this evaluation is the beta energies of the fission product mixture. The average weighted beta energy (Eg) was calculated for various decay times after shutdown.
This was done by weighting the average beta energy for each noble gas fission product (values from Reference 2) with the calculated beta skin dose at 7 mg cm-2 tissue depth for each isotope.
These values are provided in Table 4
3 and indicate that the average weighted beta energy at 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> and 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> are 0.37 MeV and 0.039 MeV, respectively.
B.
Description of Beta Sources Four beta slab sources were utilized at the University of Lowell each containing ore of the following isotopes; PM-147, TC-99, T1-204 and SR/Y-90.
Each isotope is uniformly distributed within a solid epoxy matrix which is approximately 9 inches in diameter and 1/4 inch thick. The activities and beta energies are given in Table 4 for each slab source used. These sources are considered to closaly represent the plume characteristics with respect to beta component since the dose rate at a point close to the source steface is due to nearly 1800 emissions from the source.
C.
Beta Dose Rate Measurements Each slab source was covered with 7.6 mg cm-2 of aluminized mylar and beta dose rates were measured using the YAEC extrapolation chamber at distances from the source corresponding to the center of the detector for each survey meter to be evaluated. These distances are 14,15.5,18.5 and 35 mm as shown in Table 5 for each instrument.
It should be noted that the R02A was evaluated which is not on the list from Reference 1.
This was done to provide a baseline example of a good instrument design for the purpose of this work. The extrapolation chamber measurements
,)
were performed using a 6 cm diameter collecting electrode and a 1
voltage gradient of 10 Volts per mm.
The results of these i
measurements are provided on Table 6.
D.
Gamma Dose Rates In order to produce the desired beta to gamma dose ratios, a wide range of gamma dose rate is needed due to the wide ranges of beta dose rates as shown in Table 6.
The needed range is from 5 mR/hr to 1160 mR/hr.
In order to achieve this wide range, two Cs-137 point sources were used as follows; Source 1 6 m Ci
= 6.25 mR/hr at 2 feet,12/15/83 Source 2 3 Ci
= 1937 mR/hr at 2 feet,12/15/83 w
D. Weyman March 14, 1984 Page 5 The above exposure rates were determined f rom Victoreen Condenser R chamber measurements by the University of Lowell.
These measurements are traceable to the NBS.
Based on thesdata contained in Table 6 and the desired beta to gamma dose ratios, the required gamma dose rates were calculated and the distance from the appropriate source determined by the j
inverse square law.
1j E.
Survey Meter Measurements At a calculated distance from U.e gamma source, the slab source was positioned in contact with the survey meter between the gamma source and detector.
A reading was obtained with bo'.h closed window and open window facing the slab source.
This was repeated for the 'four ratios and for each slab source. The data for each survey meter is shown in Tables 7, 8, 9, and 10.
IV.
RESULTS AND DISCUSSIGN The open and closed window response values from Table 7 through 10 are given as R /Rc and shown on Table 11 along with values of Ds/Dy g
from equation 5 and the D /D3 ratios.
It is immediately obvious 7
f rom the results on Table 11, that the PIC-6A may be eliminated as a candidate survey meter for plume survey purposes since all but one value of Ro/Rc exceeds 1.0.
Prior to evaluating the other instrument response ratios, it should be noted that the closer the Ro/Rc values are to the Ds/Dy values, the better the characteristics of the instrument. Also, the Sr/Y-90 results are not appropriate for plume environments since the average beta energy exceeds that of an anticipated plume as seen on Tables 3 and 4.
U E-520 Results These results show that the response values (Ro/Rc) only-
.j exceed 1.0 at T1-204 (E8 =.269MeV). These values show that the 1
range of overresponse with the open window is from 4 to 40 percent depending on the specific conditions.
It would be expected, however, that the actual ratios in a plume environment may be somewhat h'.gher due to the presence of non-equilibrated photoelec'.ric and compton electrons under some conditions. This additioral increase should not significantly alter the indicated results.
PRM-4 Results As in the case of the E-520 response, values greater than unity only appear at T1-204. The actual response values may be even higher than that for the E-520 because this probe provides a 4w s.
r D. Weyman March 14, 1984 Page 6 view of the plume rather than a 2w view as in the E-520.
A 4w irradiation was not performed, however, due to source geometry limitations.
Therefore, for a Ds/D ratio of 6.1, the y
expected ratio of R /R may be as high as 1.5 for T1-204. The o c Pm-147 and Tc-99 values of 1.0 would be expected to remain unchanged since the energies of the beta particles cannot significantly penetrate the detector wall.
R02-A Results These results indicate that.this instrument design is quite adequate for identifying the plume presence. The lowest ratio of Ro/Rc is 1.13 for a Ds/D ratio of 1.52.
This implies a y
13 percent over-response for the open window measurement. The largest Ro/Rc ratio is 5.1 and is for Pm-147 at Ds/Dy of 6.1.
Even though this instrument indicates excellent beta response characteristics, its present configuration does not allow it to be used for this purpose. This detector is a f ree-air ionization chamber open to the atmosphere.
If this detector were used in a noble gas cloud, radioactivity would enter the chamber and severely distort the actual dose rate. The detector design of the R02-A is excellent for this purpose and may be used as a guide for the choice of a proper device.
V.
CONCLUSION The results provided indicate that the PRM-4 and the E-520 may be useful up to the first 30 minutes after shutdown and that the PIC-6A is not useful for this purpose. The R02-A is an excellent design; however, the present design eliminates its use due to inleakage of radioactivity into the detector.
It should also be noted that the Ds/D ratios provided are based on 7
various meteorological conditions and distances from the site for a ground level release at the plume centerline.
If an elevated release occurs and/or the location is off-centerline, the potential for having j
Ds/D values much closer to unity is great. Therefore, even an y
p instrument whose characteristics are R /Rc = D /D will not be o
s 7
(
able to identify the presence of the plume.
.a
/1 Eric' L. Darois Environmental Laboratory EJD/jmn cc:
S. T. Bard M. Marion D. E. McCurdy R. A. Mellor W. Riethle
TABLE 1 The Ratio of the Gamma Diffusion Factor to the Concentration Dif fusion Factor. (X/0)v/(X/0)c For Various Stability Classes.
Downwind Distances, and Decav Times (X/0) Y/ (X/0)
Average Atmospheric Pasauil Stability Class Decay Gamma A
C F
- Time, Energy, Distance, mi.
Distance, mi.
Distance, mi.
T t(hrs)
E (MeV)
.5 2
10
.5 2
10
.5 2
10 0
.7
.8
.74
.76
.45
.81
.97
.19
.4
.71 l
.5
.5
.83
.74
.76
.48
.84
.97
.21
.42
.75 f
7
.2
.89
.74
.76
.56
.90
.97
.25
.52
.85 1
20
.1
.92
.74
.76
.65
.93
.97
.30
.58
.85 100
.05
.96
.75
.76
.75
.95 1.0
.41
.71
.92 l
TABLE 2 8 eta and Gamma Dose Conversion Factors Versus Decay Time 0
T 0
T DegggrI)***
f (t) f (t) f (t)/ f(t) 0 1.54 1.60 1.03
.5 3.88 1.96 1.97 7
8.75 5.0 1.75 20 13.0 11.8 1.10 100 26.6 29.9 0.89 s
J
TABLE 3 Determination of Minimum and Maximum Ratios of D /Dg D
y (X/0)Y (X/0)c D,7 g D
/
B T
0 Y
t(hrs)
E (MeV)
E (MeV) f (t)/f (t)
Max.
Min.
Max.
Min.
0
.7
.37 1.03
.80
.19
.82 0.196
.5
.5
.23 1.97
.97
.21 1.91 0.41 g
[
7
.2
.074 1.75
.97
.25 1.70 0.44 20
.1
.039 1.10
.97
.30 1.06 0.33 100
.05 0.89 1.0
.41 0.89 0.36 B
TABLE 4 8 eta Slab Source Specifications k9868e ah )
[(MeV)
Activity, mci Date Pm-147
.225
.064 3.6 7/17/81 i
.292
.107 3.0 7/22/81 o['
T1-204
.764
.269 2.0 8/11/82 h
Sr/Y-90 2.26 0.801 0.120 6/05/81 s
TABLE 5 Distance to Detector Centerlines. Z.
For Each Survey Meter Distance to Centerline, Survey Meter
- 2. mm
)
h PRM-4 (GM) 14 4
E-520 15.5 fj PIC-6A 18.5 R02-A 35 TABLE 6 Beta Dose Rates From Slab Sources
-2
-l Under 7.6 me cm Absorber Thickness, mrad hr Source Z = 14mm Z = 15.5mm Z = 18.5mm Z = 35m Pm-147 44.15 43 39.1 25.8
)
Tc-99 204 201 192.4 156 T1-204 608 602 587 511.4 Sr/Y-90 149 148 144.8 123.3
v;
~
TABLE 7 Results of PRM-4 Survey Meter Irradiations Z = 14mm 0,7 g D
1.91 0.8 0.41 0.196 D (mrad hr-I)
DSI) RI ) R(2) D R
R 6
R R
0 R
R B
S re c'3 o
c 3
0 3_
1 o
c 3
o l
Pm-147 44 84 80K 80K 36 40K 40K 18 20K 20K 8.5 11K 11K Tc-99 204 390 offscale 167 170K 170K 84 80K 80K 40 50K 50K I
high l
i T1-204 608 1160 offscale 500 offscale 250 offscale 120170K 140K high high high Sr/Y-90 149 285 offscale 122180K 130K 61 120K 00K 30 100K 30K high (1) Dy in units of mR/hr (2) Ro and Rc represent window open and closed respectively, in units of cpm b
t f-i
,,,---.,-n,
TABLE 8 Results of E-520 Survey Meter Irradiations Z = 15.5mm D D yj B 1.91 0.8 0.41 0.196 D (mrad hr-I)
DII) DI2) RI2) D R
R D
R R
D R
R B
S re p
2 o
c
_1 o
c
_1 o
c
_1 o
c Pm-147
.43 82 80K 80K 35 36 36 18 20K 20K 8.2 7 7
s Tc-99 201 384 380 380 165 160 160 82 80 80 38 40 40 T1-204 602 1150 1250 1200 494 600 500 247 300 250 114 170 120 Sr/Y-90 148 283 320 280 121 160 120 61 110 60 28 70 26 (1) Dy in units.of mR/hr (2) Ro and Rc represent window open and closed respectively, in units of mR/hr i
'i 9
9 e
2, t
o TABLE 9 Results of PIC-6A Survey Meter Irradiations Z = 18.5mm D D vj g 0.M6 Beta D (mrad br~I)
DII) DI)RI)D R
R D
R R
D R
R S
Source o
c 1
o c
3 o
c 3
0 x3 i
Pm-147 39 75 32 16 7.0 7.0 7.5 3.5 3.5 Data Data l
Tc-99 192 367 157 79 60 60 38 21 21 l
Not Not T1-204 587 1121 481 246 200 200 115 90 90 9
Taken Taken Sr/Y-90 145 277 119 60 50 50 28 25 20 (1) Dy in units of mR/hr
~
(2) Ro and Rc represent window open and closed respectively, in units of mR/hr.
2
-i 9
i
?
l
(-
3 TABLE 10 Results of R02-A Survey Meter Irradiations Z = 35mm v/ 8 i
1.91 0.8 0.41 0.196 D (mrad hr-I)
DII) DI)RI)D R
R D
R R
D R
R B
S re v
o c
y o
c y
o c
y o
c Pm-147 25 45 50 40 21 37 24 10 25 10 5.0 21 4.1 Tc-99 156 298 360 300 128 182 121 64 120 50 31 80 34
.l T1-204-511 976 1350 1200 419 650 415 210 450 200 100 250 100 Sr/Y-90 123 235 275 240 100 140 95 50 80 40 24 60 27 1
(1) Dy in units of mR/hr (2) Ro and Rc represent window open and closed respectively, in units of mR/hr i
!~
O
y TABLE 11 Comparison of Ro/Rc to Ds/DY for Each Survey Meter and Beta Source for the Four Ds/DY Ratios Beta Ro/Rc Source Ds/Dy PRM-4 E-520 PIC-6A R02-A Pm-147 1.52 1.0 1.0 N/A 1.25 2.22 1.0 -
1.0
~
N/A 1.54 3.43 1.0 1.0 1.0 2.54 6.10 1.0 1.0 1.0 5.10 3
h, Tc-99 1.52 N/A 1.0 N/A 1.20 2.22 1.0 1.0 N/A 1.50 3
3.43 1.0 1.0 1.0 2.40 l
6.10 1.0 1.0 1.0 2.40 T1-204 1.52 N/A 1.04 N/A 1.13 2.22 N/A 1.2 N/A 1.56 3.43 N/A 1.2 1.0 2.25 6.'10 1.21 1.4 1.0 2.50
-Sr/Y-90 1.52 N/A 1.14 N/A 1.15 2.22 1.38 1.33 N/A 1.47 i
3.43 2.88 1.83 1.0 2.0 j-6.10 3.33 2.69 1.25 2.22 I
.