ML20199E601

Amended Registry of Radioactive Sealed Sources & Devices Safety Evaluation of Device for Models SIH-24,AIB-10 & Ai Series.Certificate:NR-355-D-106-E

ML20199E601
Person / Time
Issue date:	10/01/1996
From:	Steven Baggett, Doug Broaddus NRC
To:
Shared Package
ML20199E492	List: ML20199E490 ML20199E501 ML20199E563 ML20199E569 ML20199E583 ML20199E601 ML20199E618 ML20199E649 ML20199E654 ML20199E660 ML20199E672 ML20199E705 ML20199E714 ML20199E771
References
SSD, NUDOCS 9802020203
Download: ML20199E601 (10)

Text

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REGISTRY OF RADIOACTIVE SEALED SOURCES'AND DEVICES

' SAFETY EVALUATION OF DEVICE (AMENDED-IN-ITS ENTIRETY)

-O n.NR-0355-D-105-E PATI: october 1, 1996-PAGE 1 OF-3 l

DEVICE TYPE:

Smoke Detector.

5 MODEL:

'SIH-24, AIB-10, AI_ Series Hochiki America Corporation MANUFACTURER / DISTRIBUTOR:.

i 5415 Industrial Drive Huntington Beach,.CA 92649 SEALED SOURCE MODEL E ESIGNATION:

NRD Model A-001 Amersham Model AMM1001 l-ISOTOPE:-

MAXIMUM ACTIVITY:

- Americium-241 1,0' microcurie (37.0 kBq) i LEAK._,IEST FREOUENCY:

Not required i.

PRINCIPAL-USE:

.(P) Ion Generator, Smoke Detectors CUSTOM DEVICE:

YES X

NO i

i s

i 9802020203 980108 PDR RC SSD PDR

• i.

~s-REGISTRY ~OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE (AMENDED IN ITS ENTIRETY)

- Equi NR-0355-D-105-E DATE: October 1, 1996 PAGE 2 OF 3 DEVICE = TYPE:

Smoke Detector DESCRIPTION:

-The SIH-24 and AIB-10 smoke detectors are industrial type detectors connected to and operated from a central fire control 5

unit.

These detectors are designed such_that the_ radioactive material is not-readily accessible to insu 11ers or users.

The SIH-24 and AIB-10 use the same ion chamber.

The only physical difference between the SIH-24 and the AIB-10 is in the overall size of the detectors, and that the SIH-24 has a small LED.

The SIH-24 is approximately 4' (10 cm) in diameter and 1.5" -(3.8 cm) i in height. _The AIB-10 is approximately 3" (7.5 cm) in diameter and 1.75" (4.4 cm) in height.

The AI_ Series smoke detectors-are also industrial type detectors that are connected to and operated from a central fire control 1

unit.

The series includes the models AIE and AIC detectors.

The basic fonichamber design and construction-for the two models within the series is essentially similar. -Cosmetic differences, including different outer cases, account for slight diniensional differences.

The following is a comparison of the ion chamber construction:

Descriotion AIE AIC 4

. Isotope / Activity Am-214, 1.0 pCi Am-241, 0.98 pCi Source Holder Diameter 0.44" (11.2 mm) 0.44" (11.2 mm)

Inner Electrode Length

0. 71"- (18 mm) 0. 3 5 " - ( 9 mm)

Intermediate Electrode 1.65" (42 mm) 1.46" (37 mm)

Diameter Outer Electrode 1.97" (50 mm) 1.73" (44 mm)

Diameter Hochiki distributes these detectors under different trade names, and includes the different product codes on the point of sale labeling.

--g,,:3-REGISTRY OF' RADIOACTIVE SEALED SOURCES ANP DEVICES SAFETY EVALUATION OF. DEVICE (AMENDED IN ITS ENTIRETY) 4 HQ 1 NR-0355-D-105-E DATE: October 1, 1996 PAGE 3 OF 3 DEVICE TYPE:

Smoke Detector

REFERENCES:

The following supporting documents for the smoke detector models 4

SIH-24, AIB-10 and AI Series are hereby incorporated by reference

' and are made a part of this registry document.

[

• Hochiki America Corporation's applications dated. August 22, 1995, and June 7, 1996, with enclosures thereto.

• Hochiki America Corporation's facsimiles dated December 7, 1994, June 18, 1996, July 1, 1996, July 2, 1996, August 14, 1996, August 19, 1996, September 19, 1996, and September 27, 1

1996, with enclosures thereto, t

• Hochiki America Corporation's letters dated November 24, 1987, November 25, 1989, June 25, 1990, September.5, 1990, June,2, 1994, November.30,-1994, and Junev7, 1996, with enclosuras thereto.

• NRD Incorporated's telefax-dated March-26, 1991, with-enclosures thereto.

ISSUING AGENCY:

U.S. Nuclear Regulatory Commission M.

. Date:

October 1.

1996 Reviewer:

n'<.

o-D6uglas A. Broaddus

// N - 2/' CV Date:

October 1, 1996 Concurrence:.,/

Steve'n L. Baggett i

9

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(A Y dI prbb y ct.TcNa Assuming the same person was also exposed as in example 1, the estimated dose would be: Body 0.12 + 0.02 = 0.14 mrems/y. hands, 12.6 + 0.14 = 12.7 mrems/y.

Example 6 A person who transports 10 cartons containing 100 detectors each, totaling 1000 detectors across country traveling 4000 miles. %e trip took 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br /> traveling at 50 mph. He estimated dose would be: 0.16 X 80 = 12.8 urems/y or.013 mrems/y. He same person making the trip 10 more times during the year would have an estimated dose of 0.13 mrems/y. If the same person were exposed as in example 1 in addition to the 10 trips made yearly, the estimated dose would be: 1 -

trip,0.013 + 0.01 = 0.023 mrems.10 - trips, O.13 + 0.01 = 0.14 mrems.

EATERNAL EXPOSURE.

SUMMARY

All of the examples used are very conservatim in scope, such as distances, proximity to the source, and exposure times. Examples given do not take into consideration the shielding effect provided by packaging or other materials. All the preceding estimates are far less than the limits in 10 CFR 32.28, Column I (5 mrems/y body and 75 mrems/y hands), so it is very unlikely that these limits will be exceeded.

DOSE COMMITMENI In the following section on Dose Commitment, several unusual examples, such as Gres, sre considered. While the Dose Commitments may be higher in these cases, the extemal exposure to such personnel as described will be negligible because of the short exposure timcs.

Calculations of the annual intake of AM-241 to produce a 50 year dose comnitment of 0.005 rems, based on the report ofICRP Committee 11 on Permissible Dose for Intemal Radiatim follow:

4 4

R = EF (RBE) n (a)(3.7 X 10 XJ600 X 24 X 365 X l.6 X 10 )

100 m Where EF (RBE) n = effective absorbed energy per dis, MeV q = uCi of Am-241 deposited in organ of reference m = mass of organ of reference, grams 3.7 X 10 ' = dis /sec per uCi 3600 X 24 X.565 = sec/ year 1.6 X 10' = ergs per MeV 100 = crgs/ grams per rad and R is in units of rems / year R = EF (RBE) n a = (1.867 X 10*)

m If bone is the organ of reference, EF (RBE) n = 280, and m = 7 X 10', and R = 280 q 7000 4

= (1.867 X 10 ) = 747 q rems / year.

11

He integrated dose over 50 years is:-

t d

D=.ll(1 - e A )

~A

,Where R = rems / year A = the elimination constant =.0.693fi' years

• T ~= the effective half-life, years t = the time of consideratim, years = 50'and D is in rems -

For Bone, T is 5.1 X 10* days or 140 years, and D = (747 o)(l40)(1 - e *) = 3.30 X 10 q rems -

4 0.693 l

For the limiting dose of 0.005 rems, 1

a=.9.005

= 1.5 X 10' uCi

'/.I 'M-7[N K

4 3.3 X 10 De fraction of Am-241 inhaled which reaches the bone, Fa is 0.063, so the amount of AM-241

' inhaled per year to produce a 50 year dose of 0.005 rems, Qa is:

.a 3 s to yG l(l-Z pC A

1.5 X 10' = 2.4

• 10 uCi l' U^ N 4

0 063 6

- (e l L Similarly, the fractior. reaching the bone through ingestion, fis 2.5 X 10 and Qw is 1.5 X 10 = 6.1 X 10~3 by ingestion.

jfp 8

2.5 X 10

@te r V

- Another set of calculations using "Whole Bod) ' as the organ of reference was made: 1EF (RBE)n 4

= 57; m = 7 X 10 grams 4

T = 1.8 X 10 days or 49.3 years; fa = 0.25; f = 10-'

- His resulted in anmaal intake of Am-241 to produce a dose of 0.0005 rems in 50' years as follows:

( Qa = 3.7 X 10 uCi by inhalation Qw = 9.1 X 10'2 uCi by ingestion Comparing these values with similar ones for bone, it is obvious that bone is the more critical organ. Similar calculations for other organs (limiting dose is 0.015 rems) also showed that bone is

- the most critical organ. Herefore, all of the estimated dose comnutments that follow are based on i

bone as the critical organ. ' Here is no evidence that Am-241 becomes airbome from sources previously described. Placing an upper limit on zero is difficult but will be done in order to estimate an upper limit on dose commitment.,ORNL Report TM-2684 summarizes a number of g

tests performed on 12 smoke detectors which had been in rvice at least 5 years. He detectors 12 0

, C-cpy

contained a total of 78 foils (some Ra 226, some Am-241) and contained 20 to 130 uCi per detector. Foil construction was similar to what has been previously described. Some pertinent results olthese tests were:

1. Only one of the smear tests on the extemal surface of the 12 detectors showed detectable alpha activity, and this was 20 Nm.

2. De average removable contamination on the Am 241 foils, as measured by smear tests, was 694 d/m.

3. Following a "12-week Environmental Test" at 110 degrees F and 80% relative humidity, on 20 foils (12 Ra-226, 8 Am-241), half of which were intentionally damaged. Dem was no detectable contamination on the interior surfaces of the test diamber, as measund by a smear test.

- i ring I hour " Fire Tests"(925 degrees C for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />), the average loss from Am 241 foils was 31 %

the loss which was deposited _on filters or became airbome, was 0.002%. De ORNL indicates that there was no detectable contanunation on the interior surfaces of the test l

chamber aAer the "12-Week Environmental Test." From the, port, lewis down to 6 d/m could be l

detected, so it would be reasonable to assume that at leat 20 d/m would have been detected on a smear test of the chamber. Also, from the report, it is noted that a total of 0.1;! uCi were available to become aiitome, as measured by smear tests on the foils at the beginning of the test.- his amount is approximately 25 times tha permissible contamination (0.005 uCi) on the foils used in production of the detectors and as measured by smear tests. Ifit is assumed that the sample in the ORNL Tests represented at least 4% of the chamber area, and 20 d/m could be detected, the

~

maximum that could be released form a foil iu a year would be:

20 x $2_ = 87 d/m or 3.9 X 10 uCi k

12 e

if this detector were in a room of 4 X 5 X 3 meters, and there was one air change per hour, the concentration average over a year would be:

3.9 X 10'8

= 7.4 X 10'"uCi/cc 4 X 5 X 3 X 10'X 24 X 365 He above represents a maximum concentration of a room in a residence. Similarly, if a work place had a volume of 8 X 10 X 6 cubic meters, the concentration average over a year would be:

9.3 X 10'" uCi/cc if a person were exposed as in Example I for 12 of the 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> per day at home and breathed lg 10' cc inthis 16 6e ner=i. his annual intake of Am-24 I would be:

i (7.4 X 10-")(l X 10') X 12/16 X 365 = 2.0 X 10'" uCi/y I

Also, as in Example 1, if the same person were exposed at work to 9.3 X 10'" uCi/cc in this 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> por day and breathed 1 X 10'cc in this 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> his annual intake of Am-241 would be (9.3 X 10-")(1 X 10')X 5 X 50 = 2.3 X 10 uCi/y 13

@h W q

)h l

7 (He total intakes would be 2.2 X 10 uCi/y. As calculated previously, inhalation of 2.4.X 104 uCi/y would result in a 50 year dose commitment of 0.005 rems. He dese commitment from an 7

intake of 2.2 X 10' uCi/y would therefore be:

2.2 X 10(0.005) = 0.00046 rems 2.4 X 10 -

4 l

1 He above is intended to be an upper limit on zero, since there is no evidence to show that Am 241

-l becomes airbome under normal conditions. It can also be said that in Examples 2 6 previously' described, that there is a negligible release of Am-241 to be respirable, even though quantities of i

100 or 1000 detectors are involved.

C gQ?

Estimated Dose Commitments under abnormal conditions are calculated in the following examples:

Example 7 If a fire should occur in a 4 X 5 X 3 meter room, an 0.3 of the 0.5 uCi Am-241 source should become airbome, the aveage concentration might be:

0.0031 X 0.5

= 2.6 X 10 " uCi/cc 4 X 5 X 3 X 10'

-7

(

g g

if a person were to remain in this room for 5 minutes, he might inhale:

). h fo '*

• f. h u h h * # N t' 4 C

2.6 X 10'" X 2 X 10' X 5 = 1.8 X 10 uCi

/pj co,

4 r

60 X 24.

If as previously calculated, inhalation of 2.4 X 10* uCi/y would result in a 50 year dose 4

commitment of 0.005 rems, inhalation of 1.8 X 10 uCi would result in a 50 year dose commitment of approximately 0.00375 rems.

Example 8 If a fire occurred in an area having i volume of 8 X 10 X 6 cubic meters and containing 10 detectors, and 0.31% of the 50 uCi becarae airbome, the average ccacentration might be:

0.0032 X 50

= 3.2 X 10 uCi/cc 8 X 10 X 6 X 10' However, it would take some period of time for the airbome contamination to become evenly distributed in a room of this size. He heat from such a fire would preclude any person from being in close proximity of the fire. Here would be at least a dilution factor of 10 to where a person might be during the first few minutes of the fire. Assuming a person might take 5 minutes to evacuate, he might inhale:

3.2 X 10'" X 2 X 10' X 5

= 2.2 X 10 uCi 4

60 X 24 14

His corresponds to a 50 year dose comriitment of:

4 2.2 X 10 (0.005) = 0.005 rems 4

2.4 X 10 If a person fighting the fire would enter the room after the airbome contamination had been distributed throughout the volume, and the person was not wearing a respirator and he remained

' 1/2 an hour, he might inhale:

3 2 X 10 X 2 X 10' = 1.3 X 10' uCi 2 X 24 Note: Water or other fire-fighting materials would tend to reduce the airbome contamination. His corresponds to a 50 year dose commitment of:

d 1.3 X 1O (0.005) = 0.27 rems 2.4 X 10

• Example 9 If a fire should occur in an area having a volume of 30 X 50 X 6 cubic meters and there were 1000 detectors present and 0.31% of the 500 uCi became airbome, the average concentration would be:

0.0031 X 500

= 1.7 X 10 uCi/cc 30 X 50 X 6 X 10' Again assuming there would be a dilution factor of at 10 where a person might be during the first few minutes of the fire, and delayed his exit for 5 minutes, the person might inhale:

1.7 X 10'" X 2 X 10' X __

5

= 1.2 X 10 uCi 4

60 X 24 This corresponds to a 50 year dose commitment of:

4 1.2 X 10 0.005) = 0.0025 rems 4

2.4 X 10 If a fire fighter entered the area after the airborne contamination had distributed throughout the volume, and was not wearing respiratory prctection, and he remained for 1/2 hour, he might inhale:

1.7 X 10 X 2 X 10'= 7 X 10%Ci 2 X 24 Ris corresponds to a 50 year dose conunitment of:

7.0 X 10'8 (0.005) = 0.15 rems 2.4 X 10*

15

=v<-.

Example l'0 A person who would be c'.earMg up after the fire described in Example 9 might be expM to 0.0031 X $00 = 1.6 uCi of contamination which might have become airbome. Dunstei Health Physics (Vol. 8, No. 4, nug. "62") indicates t. re suspension factor when rummaging through dusty building rubble in an enclosed and unventilated space would be:

2 X 10* m

- Assuming the 1.6 uCi were in an area of 6 % 6 square meters, the concentration in the room would be:

d g

4 4

8

' l.6 X 2 X 10 = 8. X 10 uCi/m or 8.9 X 10 " uCi/cc.

6X6 If a person were to work 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> under these conditions, he might inhale:

_7 b

$. >,_ X 0 p

/ i Y O.t N l')~yt.o'<j \\

c 8.9 X 10'" X 2 X 10' X 8 = 6,0 X 10 uCi

{

p1

/

24 His corresponds to a 50 year dose commitmeiet of:

6.0 X 10l( 0.005) = 0.001 rems 2.4 X 10*

Example 1I in the unlikely event that a person should swallow a foil and the total activity (0.5 uCi) were 4

ingested as previously calculated, and the quantity ingested in a year is 6.1 X 10 uCi to produce a 50 year dose commitment of 0.005 rems, the dose commitment would be:

0.5 - (0.005) = 0.40 rems -

4 6.1 X 10 An actual case history (Health Physics, Vol. 33 No. 5, Dec.1977) indicate the scenario in above

. assumption to be extremely conservative. -He reference indicated that the foils passed in a -

reasonable time and that there was no dete table resid sal body burden.

DOSE COMMITMENT

SUMMARY

2 All of the preceding examples are considered conservative. He "ORNL Fire Test" indicated that the average loss from the Am-241 foils was 0.31%, but most of this was deposited on the tubes containing the foils, and only 0.002% became airbome and was deposited on filters. All dose commitments are less than 10 CFR 32.28; Column I limits. under normal operating conditions. In abnormal situations, the estimates indicate that Column 11 may be exceeded slightly, but they are 8~

allless than the Column 111 limits.

16

g Cross Reference chart for Hochiki America ionization smoke Detectors.

Hochiki Simplex Simplex Ini'l Radionics Model Model Model Model V

/

X D281 #

dIH 24F

/2098-9576 na.

hHeg IO98-9576C n.a.

na.

Y 98 9550 #

dIH-24EL 20 n.a.

n.a.

SIH 24FAP n.a.

9F n.a.

n.a.

++

n.a.

n.a.

++

n.a.

4098-9716C n.a.

.1 ( Y lJ-24

• S n.a.

n.a.

n.a.

bL wy

(-

~

- NOTE:

+ + These m els ar manufactured only for Simplex and Simplex intemational.

No Hochi -i Mo el exists.

1 12/9/96.

jet Ceft'<f

(

).s y d<.

f h05 4

i A.M

.