Information Notice 1996-66, Recent Misadministrations Caused by Incorrect Calibrations of Strontium-90 Eye Applicators: Difference between revisions
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{{#Wiki_filter:UNITED STATES | {{#Wiki_filter:UNITED STATES | ||
COMMISSION | NUCLEAR REGULATORY COMMISSION | ||
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS | |||
NOTICE 96-66: RECENT MISADMINISTRATIONS | WASHINGTON, D.C. 20555 December 13, 1996 NRC INFORMATION NOTICE 96-66: RECENT MISADMINISTRATIONS CAUSED BY | ||
INCORRECT CALIBRATIONS OF STRONTIUM-90 | |||
EYE APPLICATORS | |||
==Addressees== | |||
to use | |||
All U.S. Nuclear Regulatory Commission Medical Use Licensees authorized | |||
== | strontium-90 (Sr-90) eye applicators. | ||
==Purpose== | |||
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information | |||
notice to alert addressees to recent misadministrations caused by incorrect that | |||
source strength determinations of Sr-90 eye applicators. It is expected | |||
facilities | |||
recipients will review the information for applicability to their | |||
to | and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; | ||
therefore, no specific action nor written response is required. | |||
DescriDtion of Circumstances | |||
The primary causes of two recent events have been problems with calibration the | |||
and calculation of the dose rates from Sr-90 applicators. As a result, administered doses were not within 20 percent of the prescribed dose. | |||
to | to use | ||
Case 1. In October 1995, during an inspection of a licensee authorized the | |||
a Sr-90 eye applicator in Mayag~ez, Puerto Rico, it was determined that A | |||
calibration record for the licensee's Sr-90 eye applicator was missing. | |||
and | |||
previous owner of the source lost the original calibration certificate, This | |||
his medical physics consultant performed a check of the source strength. resulted | |||
and | check was performed with an inappropriate measurement instrument and 0 | ||
in an incorrect determination of the source strength as 0.24 Gray (Gy)/sec the | |||
(24 rad/sec). The licensee obtained the source in 1994 and relied on source | |||
erroneous source strength determination during treatments. Also, the | |||
in | had not been decay-corrected by either owner since 1990. NRC urged the Fc2 licensee to have the eye applicator recalibrated and to be instructed in the | ||
D | |||
of | proper method to calculate the decay of the source. | ||
National | |||
The licensee subsequently had the eye applicator recalibrated by the a | |||
of | Institute of Standards and Technology. The resultant recalibration revealed used | ||
dose rate of 0.53 Gray (53 rad)/sec rather than the 0.24 Gy (24 rad)/sec to | |||
10 | |||
by the licensee. The licensee had prescribed a total dose of between | |||
25 Gy (1000 to 2500 rad) for approximately | |||
9-0709036 f arr&0 C. Ilt, 2a | |||
Dr | |||
IN 96-66 December 13, 1996 70 patients, but actually administered about twice this amount. An NRC | |||
that the | medical consultant has reviewed the cases and has recommended that the | ||
patients be evaluated for any adverse effects. | |||
Case 2. In November 1995, while reviewing treatment records during a routine | |||
NRC inspection of a licensee authorized to use a Sr-90 eye applicator in | |||
Honolulu, Hawaii, an NRC inspector determined that the licensee had | |||
incorrectly calculated the decay of the strength of a Sr-90 eye applicator and | |||
subsequently delivered doses 20 percent over the prescribed doses to 16 patients. The root cause of this event was the licensee improperly | |||
calculating the decay of the Sr-90 source. Specifically, the licensee | |||
linearly decayed the strength of the source instead of logarithmically | |||
decaying the source strength of the eye applicator. Before May 1995, a | |||
technologist had correctly calculated the decay of the source; however, when | |||
this technologist left, the physician incorrectly calculated the source decay | |||
based on a linear decay from the previous calculations. In addition, the | |||
of the | incorrect half-life of Sr-90 was used in the calculation. | ||
Following a correct determination of the source strength, the licensee | |||
determined that 17 misadministrations involving 16 patients occurred, from | |||
May 6, 1995 to November 16, 1995, including one patient who was treated on | |||
both eyes. The delivered doses range from 21.1 to 22.7 percent greater than | |||
the prescribed dose of 40 Gy (4000 rad). | |||
Discussion | |||
10 CFR 35.32, *Quality Management Program," requires licensees to develop | |||
written procedures to meet five objectives associated with any brachytherapy | |||
the | dose, including assurance that the prescribed dose is the administered dose. | ||
A necessary part of this is to ensure that the dose rate emitted from an | |||
applicator is correct. If the manufacturer's certificate of calibration or | |||
original activity/dose rate name plate is missing, the licensee should arrange | |||
with a qualified expert to determine the dose rate from the Sr-90 source. | |||
(For additional details, see NRC IN 94-17, NSr-90 Eye Applicators: Submission | |||
of Quality Management Plan, Calibration and Use," dated March 11, 1994.) | |||
Failure to implement the Quality Management Rule and make required reports may | |||
subject a licensee to orders, civil penalties, and notices of violation. | |||
In view of the nature of the cited events, it appears worthwhile to review | |||
some of the properties of Sr-90 eye applicators and the related processes for | |||
a | decay correction over time. New Sr-90 eye applicators typically contain a | ||
2 gigabecquerel (GBq) [54 millicurie(mCi)] source, exhibiting a surface dose | |||
rate of about 0.50 Gy (50 rad)/sec. The half-life of the parent Sr-90 is | |||
28.5 yrs [maximum beta energy equal to 0.54 mega-electron volts (MeY)], and | |||
the yttrium-90 (Y-90) daughter half-life is 64.2 hrs (beta-max, 2.27 MeV); | |||
therefore, both isotopes are in equilibrium on the eye applicator. Since | |||
Sr-90 and Y-90 are in equilibrium, emissions from both isotopes must be | |||
for | accounted for in dosimetry calculations. | ||
IN 96-66 December 13, 1996 rate | |||
The dose rate (D,) at a time (t) can be calculated from the initial dose | |||
of | (De) at the time of the most recent calibration with the following formula: | ||
D = D - (e-^t) (FI) | |||
-Xt | |||
to | where e, the base of the natural logarithm (2.718), is raised to the powerT. is | ||
and is referred to as the 'decay factor' (df), where -X - -0.693/Tx, the half-life of the isotope, and t is the elapsed time. For Sr-90, TX-28.5 can | |||
years; therefore, X - (0.693)/(28.5 yrs) = 0.0243 yr'. The values for df | |||
after t | |||
be used to determine the fraction of original activity remaining | |||
the | years. These values can then be used to calculate dose rates by using the | ||
following formula: | |||
D,= Dao df (F2) | |||
The fraction of activity remaining after a given number of years from the | |||
original measurement date is given in Table 1 (Attachment 1). | |||
For example | |||
An eye applicator calibrated by the manufacturer on January 1, 1978, If, delivered | |||
on contact. on | |||
an initial dose rate ( Do) of 0.75 Gy/sec (75 rad/sec) | |||
(in | |||
the | January 1, 1996, the eye applicator needs to be used, the elapsed time | ||
years) since calibration is 18, and from Table 1, df = 0.646 for Sr-90. | |||
Using formula F2: | |||
D,= bo. df | |||
D18yaM - (0.75 Gy/sec)(0.646) | |||
bigyea - 0.485 Gy/sec | |||
(48.5 rad/sec) | |||
the | IN 96-66 December 13, 1996 Table I may be extended using formula F1 and the value X - 0.0243 yr' for | ||
Sr-90. Other values of df that need to be evaluated by licensees will need to | |||
be re-calculated by using the appropriate half-life for that isotope. | |||
Alternatively, a semi-logarithmic plot of the above data will yield a straight | |||
line, which may be extended beyond 25 years. | |||
This information notice requires no specific action nor written response. If | |||
you have any questions about the information in this notice, please contact | |||
of | one of the technical contacts listed below or the appropriate regional office. | ||
Donald A. Cool, D rector | |||
Division of Industrial and | |||
Medical Nuclear Safety | |||
Office of Nuclear Material Safety | |||
and Safeguards | |||
Technical contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 E-mail: jxd2@nrc.gov | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 E-mail: emg@nrc.gov | |||
James A. Smith, NMSS | |||
(301) 415-7904 E-mail: jas4@nrc.gov | |||
Attachments: | |||
1. List of Recently Issued NMSS Information Notices | |||
2. List of Recently Issued NRC Information Notices | |||
42 T7SSI (/4e | |||
Attachment I | |||
IN 96-66 December 13, 1996 Page 1 of I | |||
TABLE 1 FRACTION (EXPRESSED AS DECIMAL) OF ORIGINAL | |||
SR-90 ACTIVITY REMAINING AFTER (t) YEARS | |||
df Years (t) df Years (t) df Years (t) df | |||
Years (t) | |||
0.994 6.5 0.854 12.75 0.734 19 0.63 | |||
.25 | |||
6.75 0.849 13 0.729 19.25 0.626 | |||
.5 0.988 | |||
0.982 7 0.844 13.25 0.725 19.5 0.623 | |||
.75 | |||
0.976 7.25 0.838 13.5 0.72 19.75 0.619 | |||
1 | |||
0.97 7.5 0.833 13.75 0.716 20 0.615 | |||
1.25 | |||
0.964 7.75 0.828 14 0.712 20.25 0.611 | |||
1.5 | |||
0.958 8 0.823 14.25 0.707 20.5 0.608 | |||
1.75 | |||
0.953 8.25 0.818 14.5 0.703 20.75 0.604 | |||
2 | |||
0.947 8.5 0.813 14.75 0.699 21 0.6 | |||
2.25 | |||
0.941 8.75 0.808 15 0.695 21.25 0.597 | |||
2.5 | |||
0.935 9 0.804 15.25 0.69 21.5 0.593 | |||
2.75 | |||
0.93 9.25 0.799 15.5 0.686 21.75 0.589 | |||
3 | |||
0.924 9.5 0.794 15.75 0.682 22 0.586 | |||
3.25 | |||
9.75 0.789 16 0.678 22.25 0.582 | |||
3.5 0.918 | |||
10 0.784 16.25 0.674 22.5 0.579 | |||
3.75 0.913 | |||
10.25 0.78 16.5 0.67 22.75 0.575 | |||
4 0.907 | |||
0.902 10.5 0.775 16.75 0.666 23 0.572 | |||
4.25 | |||
0.896 10.75 0.77 17 0.662 23.25 0.568 | |||
4.5 | |||
11 0.765 17.25 0.658 23.5 0.565 | |||
4.75 0.891 | |||
11.25 0.761 17.5 0.654 23.75 0.562 | |||
5 0.886 | |||
11.5 0.756 17.75 0.65 24 0.558 | |||
5.25 0.88 | |||
0.875 11.75 0.752 18 0.646 24.25 0.555 | |||
5.5 | |||
0.87 12 0.747 18.25 0.642 24.5 0.551 | |||
5.75 | |||
0.864 12.25 0.743 18.5 0.638 24.75 0.548 | |||
6 | |||
0.859 12.5 0.738 18.75 0.634 25 0.545 | |||
6.25 | |||
Attachment 2 IN 96-66 December 13, 1996 Page 1 of I | |||
UST OF RECENTLY ISSUED | |||
NMSS INFORMATION NOTICES | |||
of | Information Date of | ||
Notice No. Subject Issuance Issued to | |||
96-63 Potential Safety Issue 12/05196 All U.S. Nuclear Regulatory | |||
Regarding the Shipment Commission licensees | |||
of Fissile Material authorized to possess special | |||
nuclear material in unsealed | |||
quantities greater than a | |||
critical mass | |||
96-57 Incident-Reporting Require- 10/30196 All U.S. Nuclear Regulatory | |||
ments Involving Intakes, Commission licensees | |||
During a 24-Hour Period | |||
that May Cause a Total | |||
Effective Dose Equivalent | |||
of | in Excess of 0.05 Sv (5 rem) | ||
96-54 Vulnerability of Stainless 10/17/96 All material licensees | |||
Steel to Corrosion When | |||
Sensitized | |||
96-53 Retrofit to Amersham 660 10115/96 All industrial radiography | |||
Posilock Radiography licensees | |||
Camera to Correct Incon- sistency in 10 CFR Part 34 Compatibility | |||
96-52 Cracked Insertion Rods 09/26/96 All U.S. Nuclear Regulatory | |||
on Troxler Model 3400 Commission portable gauge | |||
Series Portable Moisture licensees and vendors | |||
Density Gauges | |||
96-51 Residual Contamination 09/11196 All material licensees | |||
Remaining in Krypton-85 Handling System After | |||
Venting | |||
' > | |||
Attachment 3 IN 96-66 December 13, 1996 Page 1 of I | |||
UST OF RECENTLY ISSUED | |||
NRC INFORMATION NOTICES | |||
Information Date of | |||
Notice No. Subject Issuance Issued to | |||
96-65 Undetected Accumulation 1211 1/96 All holders of OLs | |||
of Gas in Reactor Coolant or CPs for nuclear | |||
System and Inaccurate power reactors | |||
Reactor Water Level | |||
Indication During Shutdown | |||
96-64 Modifications to Con- 12/10196 All holders of OLs | |||
tainment Blowout Panels or CPs for nuclear | |||
Without Appropriate reactors | |||
Design Controls | |||
96-63 Potential Safety Issue 12/05196 All U.S. Nuclear | |||
Regarding the Shipment Regulatory Commission | |||
of Fissile Material licensees authorized | |||
to possess special | |||
nuclear material in | |||
unsealed quantities | |||
greater than a critical | |||
mass | |||
96-62 Potential Failure of the 11120196 All holders of OLs | |||
Instantaneous Trip Function and CPs for nuclear | |||
of General Electric RMS-9 power plants | |||
Programmers | |||
96-61 Failure of a Main Steam Safety 11/20/96 All holders of OLs or | |||
Valve to Reseat Caused by an CPs for nuclear power | |||
Improperly Installed Release . reactors | |||
Nut | |||
96-60 Potential Common-Mode Post- 11/14/96 All holders of OLs or | |||
Accident Failure of Residual CPs for nuclear power | |||
Heat Removal Heat Exchangers reactors | |||
OL = Operating License | |||
CP = Construction Permit | |||
IN 96-66 | |||
. December 13, 1996 Table 1 may be extended using formula FH and the value x - 0.0243 yr1 for | |||
Sr-90. Other values of df that need to be evaluated by licensees will need to | |||
be re-calculated by using the appropriate half-life for that isotope. | |||
Alternatively, a semi-logarithmic plot of the above data will yield a straight | |||
line, which may be extended beyond 25 years. | |||
This information notice requires no specific action nor written response. If | |||
you have any questions about the information in this notice, please contact | |||
one of the technical contacts listed below or the appropriate regional office. | |||
Donald A. Cool, Director | |||
Division of Industrial and | |||
Medical Nuclear Safety | |||
Office of Nuclear Material Safety | |||
and Safeguards | |||
Technical contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 E-mail: jxd2@nrc.gov | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 E-mail: emg@nrc.gov | |||
James A. Smith, NMSS | |||
(301) 415-7904 E-mail: jas4enrc.gov | |||
Attachments: | |||
1. List of Recently Issued NMSS Information Notices | |||
2. List of Recently Issued NRC Information Notices | |||
Official Record Copy S:\Jsmith\imns5350.JAS | |||
OFC IMAB I E IMAB lIMAB I IMOB I Tech Ed I | |||
KANE JASmith SLMerchant LWCamper o JMPiccone o EKraus o | |||
DATE 1 11/26/96 11/26/96 110/28/96 10/29/96 8/01/96 OFC J IJE OGC I DD/IMNS I D/IMNS I | |||
NAME JLiebermano SATreby o FCCombso DACool | |||
DATE 08/07/96 11/07/96 11/12/96 I 11/29/96 | |||
- COWVER E = COVER & Attachment N - NO COPY o- See Previous Concurrence | |||
eIN 96-## | |||
'J November .1996 Table 1 may be extended using formula F1 and the value A = 0.0243 yr" for | |||
Sr-90. Other values of df that need to be evaluated by licensees will need to | |||
be re-calculated by using the appropriate half-life for that isotope. | |||
Alternatively, a semi-logarithmic plot of the above data will yield a straight | |||
line, which may extended beyond 25 years. | |||
This information notice requires no specific action nor written response. If | |||
you have any questions about the information in this notice, please contact | |||
one of the technical contacts listed below or the appropriate regional office. | |||
Donald A. Cool, Director | |||
Division of Industrial and | |||
Medical Nuclear Safety | |||
Office of Nuclear Material Safety | |||
and Safeguards | |||
Contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 Internet: JXD2@NRC.GOV | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 Internet: EMG@NRC.GOV | |||
James A. Smith, NMSS | |||
(301) 415-7904 Internet:JAS4@NRC.GOV | |||
Attachments: | |||
1. Table of decay factors | |||
2. List of Recently Issue(d NMSS Information Notices | |||
3. List of Recently Issue(d NRC Information Notices | |||
fffirial Rernrd COnY Svisrnith\imns5350JAS | |||
OFC IMAB lE IMAB lIMAB lIMOB j Tech Ed | |||
NAME JASmi SLM@f@I~nt LWCamper o JMPiccone o EKraus @ | |||
DATE it /96 i 10/8/ | |||
9 6 10/29/96 8/01/96 OFC OE I OGC DD/IMNS DlIMNS | |||
NAME JLieberman@ SATreby @ FCCombs@ _____ __ _ _l | |||
DATE 08/07/96 11/07/96 11/12/96 ///t11/96 | |||
= COVER E = COVER & Attachment N = NO COPY ?--See Previous Concurrence | |||
N 96-Il | |||
-November 91996 This information notice requires no specific action nor written respons . If | |||
you have any questions about the information in this notice, please c tact | |||
one of the technical contacts listed below or the appropriate reglo 1 office. | |||
Donald A. Cool, Director, Division of Industrial and | |||
Medical Nuclear Sa ty | |||
Office of Nuclear terial Safety | |||
and Safeguards | |||
Contacts: Jose M. Diaz-Velez, RI | |||
(404) 331-7438 Internet: JXD2@NRC.GOV | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 Internet: EMG@NRC.GOV | |||
James A. Smith, NMSS | |||
(301) 415-7904 Internet:JAS4@NRC.GOV | |||
Attachments: | |||
1. Table of decay factors | |||
2. List of Recently Issued NMS Information Notices | |||
3. List of Recently Issued MR Information Notices | |||
Official Record Copy 5: \smitinins5350.JAS | |||
OFC IMAB I E IMAB//1S IMAB I IMOB I Tech E | |||
NAME JASmithm SL erc nt LWCamper o JMPiccone a EKraus o | |||
DATE t//14/96 A/96 10/28/96 10/29/96 8/01/96 OFC OE l OGC DD/IMNS D/IMNS | |||
NAME JLiebermanq/ SATreby o FCCombso DACool | |||
DATE 08/07/9 11/07/96 11/12/96 / /96 C = COVER E M OVER h Attachment N a NO COPY o- See Previous Concurrence | |||
N 96-## | |||
;. | |||
a *-i ovember .1996 D | |||
18year (0.75 Gy/sec)(0.646) | |||
" | |||
blyrs, 0G0.485 Gy/sec | |||
Table 1 may be extended using formula F1 and the value A 0.0243 yr-. | |||
Alternatively, a semi-logarithmic plot of the above dat will yield a straight | |||
line, which may extended beyond 20 years. | |||
This information notice requires no specific actio nor written response. If | |||
you have any questions about the information in t s notice, please contact | |||
one of the technical contacts listed below or t appropriate regional office. | |||
Donald . Cool. Director | |||
Divis on of Industrial and | |||
M ical Nuclear Safety | |||
Ofice of Nuclear Material Safety | |||
and Safeguards | |||
Contacts: Jose M. Diaz-Velez, | |||
(404) 331-7438 Internet:JMD2@NRC. V | |||
Emilio M. Garci , RIV | |||
(510) 975-0239/ | |||
Internet:EM C.GOV | |||
James A. S ,thNMSS | |||
(301) 415- 904 Internet- AS4@NRC.GOV | |||
Attachments: | |||
1. List of Recent y Issued NMSS Information Notices | |||
2. List of Rece ly Issued NRC Information Notices | |||
Official Recordo S:\jsmith\imns5350.JAS | |||
OFC | |||
NAME | |||
DATE / | |||
IMA | |||
/1*196 E | |||
I IMAB | |||
le/6///96 ant | |||
jI I | |||
LWCamper o | |||
10/28/96 II MOB | |||
JMPiccone | |||
10/29/96 | |||
@ | |||
Techi Ed | |||
EKraus o | |||
8/01/96 OFC/ OE I OGC DD/IMNS D/IMNS l | |||
AM JLiebermano SATreby o FCCombso DACool | |||
N | D0/07/96 11/07/96 11/12/96 / /96 | ||
,COVER E = COVER & Attachment N = NO COPY @- See Previous Concurrence | |||
N 96-ft | |||
<iovember ,1996 D (0.75 Gy/sec)(0.646) | |||
.0.485 Gy/sec | |||
1 Table 1 may be etended using formula F1 and the value X - 0.0243 yr . | |||
Alternatively, a mi-logarithmic plot of the above data will yield a straight | |||
line, which may ext nded beyond 20 years. | |||
This information noti requires no specific action nor written response. If | |||
you have any questions bout the information inthis notice, please contact | |||
(one of) the technical c tact(s) listed below or the appropriate regional | |||
office. | |||
Donald A. Cool, Director | |||
Division of Industrial and | |||
Medical Nuclear Safety | |||
Office of Nuclear Material Safety | |||
and Safeguards | |||
Contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 Internet:JMD2@NRC.GOY | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 Internet:EMG@NRC.GOV | |||
James A. Smith, NMSS | |||
(301) 415-7904 Internet:JAS4@NRC.GOV | |||
Attachments: | |||
1. List of Recently Issued NMSS Information Notices | |||
2. List of Recently Issued NRC Information Notices | |||
Official Record Copy S:\Jsmith\imns5350.JAS \ | |||
OFC qIMABiLW B IM4AB - l | |||
IMOB E\Tech Ed | |||
NAME JASm1i SL chant LWCamper a JMPiccone c EKraus o | |||
DATE I I 1/96 _ / j 10/28/96 10/29/96 8/01/96 OFC OE OGC DD/IMNS D/IMNS | |||
NAME JLiebermano SATreby a F(Cm DACool | |||
DATE 08/07/96 11/07/96 / /96 C a COVER E a CUVLK & Attacnment N = mU LUr1'u- aee rrevmuUs IA0ICUIIrCLM. | |||
,N96-## | |||
' "-'-6ctober ,1996 ble8.. - (0.75 Gy/sec)(0.646) | |||
l 0.4 y/sec | |||
Table 1 may be extended using fo ula F1 and the value X - 0.0243 yre. | |||
Alternatively, a semi-logarithmic lot of the above data will yield a straight | |||
line, which may extended beyond 20 ars. | |||
This information notice requires no sp ific action nor written response. If | |||
you have any questions about the infrma ion inthis notice, please contact | |||
(one of) the technical contact(s) listed elow or the appropriate regional | |||
office. | |||
Donald A. -ool, Director | |||
Division o Industrial and | |||
Medical Ntclear Safety | |||
Office of N clear Material Safety | |||
and Safegu rds | |||
Contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 Internet:JMD2@NRC. GOY | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 Internet:EMG@NRC.GOV | |||
James A. Smith, NMSS | |||
(301) 415-7904 Internet:JAS4@NRC .GOV | |||
Attachments: | Attachments: | ||
1. List of Recently Issued NMSS Information | 1. List of Recently Issued NMSS Information Notices | ||
2. List of Recently Issued NRC Information Notices | |||
Official Record Copy S:\Jsmithi\mns5350.JAS \ | |||
OFCIMAB AB IMAB I l IMOB l \l,TechEdl | |||
NAME JASai R SUM nt LWCamper a JMPiccone o EKraus o | |||
DATE / -J/ 10/28/96 10/29/96 8/01/96 OFC OE DD/IMNS D/IMNS | |||
KANE JLiebermano Sireb NIL FCCombs DACool | |||
DATE 08/07/96 l/ /1/96 / /96 / /96 aCOVER E a COVER & Attachment K = ND COPY o- See Previous Concurrence \ | |||
, | C,6 I < ~N96-#t | ||
,1996 | 4 October ,1996 We have Dlew. - (0.75 Gy/sec)(0.646) | ||
Table I may be extended using formula FH and the value X - 0.0243 yr1 . | |||
Alternatively, a semi-icgarithmic plot of the above data will yield a straight | |||
line, which may extended be~yond 20 years. | |||
If | This information notice requires no specific action nor written response. If | ||
about the | you have any questions about the information in this notice, please contact | ||
contact(s) | (one of) the technical contact(s) listed below or the appropriate regional | ||
listed | |||
office. | |||
Donald A. Cool, Director | |||
Division of Industrial and | |||
Medical Nuclear Safety | |||
Office cf Nuclear Material Safety | |||
and Safrguards | |||
Contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 Internet:JMD2@NRC.60V | |||
Emilio M. Garcia, RIV | |||
(510) 975-0239 Internet:EMG@NRC.GOY | |||
James A. Smith, NMSS | |||
(301) 415-7904 Internet:JAS4@NRC.GOV | |||
Attachments: | |||
1. List of Recently Issued NMSS Information Notices | |||
2. List of Recently Issued NRC Information Notices | |||
Official Record CODY SA:smithkimtns535GJAS | |||
OFC IMAB E IMAB Tech | |||
NAME JASmi S rchant C rer on EKraus o | |||
DATE It/1 /96 /96 96 /09 /96 8/01/96 OFC OE lOGC lDD/IMNS l D/IMNS l~ | |||
KANE JLiebermano SATreby FCCombs DACool | |||
DATE 08/07/96 / /96 I /96 / /96 | |||
:* COVER E a COVER & Attachment N = NO COPY e- See Previous Concurrence | |||
A ' | |||
IN 96-## | |||
August ,1996 This informat n not1ce requires no specific action nor written response. If | |||
you have any qu tions about the information in this notice, please contact | |||
(one of) the techn cal contact(s) listed below or the appropriate regional | |||
office. | |||
Donald A. Cool, Director | |||
Division of Industrial and | |||
Medical Nuclear Safety | |||
Office of Nuclear Material Safety | |||
and Safeguards | |||
Contacts: Jose M. Diaz-Velez, RII | |||
(404) 331-7438 Emilio M. Garcia, RIV | |||
(510) 975-0239 James A. Smith, NMSS | |||
(301) 415-7904 Attachments: | |||
1. List of Recently Issued NMSS Information Notices | |||
2. List of Recently Issued NRC Information Notices | |||
Official Record Copy G:\imns5350.JAS , ) | |||
OFC IMABl E IlTech | |||
OGC Ed | |||
NAME JASmi'W per SATreby EKraus a | |||
DATE *in /96 __ /________ \___96 / /96 8/01/96 OFC \ IlI DD/IMNS l D/IMNS l | |||
NAME Q jeerman FCCombs DACool | |||
DATE ___9_ | |||
: w COVER | |||
N = NO COPY o- See Previous Concurrence}} | / /96 | ||
'E i. COVER & Attachment N = NO COPY o- See Previous Concurrence}} | |||
{{Information notice-Nav}} | {{Information notice-Nav}} |
Latest revision as of 04:40, 24 November 2019
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555 December 13, 1996 NRC INFORMATION NOTICE 96-66: RECENT MISADMINISTRATIONS CAUSED BY
INCORRECT CALIBRATIONS OF STRONTIUM-90
EYE APPLICATORS
Addressees
to use
All U.S. Nuclear Regulatory Commission Medical Use Licensees authorized
strontium-90 (Sr-90) eye applicators.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to recent misadministrations caused by incorrect that
source strength determinations of Sr-90 eye applicators. It is expected
facilities
recipients will review the information for applicability to their
and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements;
therefore, no specific action nor written response is required.
DescriDtion of Circumstances
The primary causes of two recent events have been problems with calibration the
and calculation of the dose rates from Sr-90 applicators. As a result, administered doses were not within 20 percent of the prescribed dose.
to use
Case 1. In October 1995, during an inspection of a licensee authorized the
a Sr-90 eye applicator in Mayag~ez, Puerto Rico, it was determined that A
calibration record for the licensee's Sr-90 eye applicator was missing.
and
previous owner of the source lost the original calibration certificate, This
his medical physics consultant performed a check of the source strength. resulted
check was performed with an inappropriate measurement instrument and 0
in an incorrect determination of the source strength as 0.24 Gray (Gy)/sec the
(24 rad/sec). The licensee obtained the source in 1994 and relied on source
erroneous source strength determination during treatments. Also, the
had not been decay-corrected by either owner since 1990. NRC urged the Fc2 licensee to have the eye applicator recalibrated and to be instructed in the
D
proper method to calculate the decay of the source.
National
The licensee subsequently had the eye applicator recalibrated by the a
Institute of Standards and Technology. The resultant recalibration revealed used
dose rate of 0.53 Gray (53 rad)/sec rather than the 0.24 Gy (24 rad)/sec to
10
by the licensee. The licensee had prescribed a total dose of between
25 Gy (1000 to 2500 rad) for approximately
9-0709036 f arr&0 C. Ilt, 2a
Dr
IN 96-66 December 13, 1996 70 patients, but actually administered about twice this amount. An NRC
medical consultant has reviewed the cases and has recommended that the
patients be evaluated for any adverse effects.
Case 2. In November 1995, while reviewing treatment records during a routine
NRC inspection of a licensee authorized to use a Sr-90 eye applicator in
Honolulu, Hawaii, an NRC inspector determined that the licensee had
incorrectly calculated the decay of the strength of a Sr-90 eye applicator and
subsequently delivered doses 20 percent over the prescribed doses to 16 patients. The root cause of this event was the licensee improperly
calculating the decay of the Sr-90 source. Specifically, the licensee
linearly decayed the strength of the source instead of logarithmically
decaying the source strength of the eye applicator. Before May 1995, a
technologist had correctly calculated the decay of the source; however, when
this technologist left, the physician incorrectly calculated the source decay
based on a linear decay from the previous calculations. In addition, the
incorrect half-life of Sr-90 was used in the calculation.
Following a correct determination of the source strength, the licensee
determined that 17 misadministrations involving 16 patients occurred, from
May 6, 1995 to November 16, 1995, including one patient who was treated on
both eyes. The delivered doses range from 21.1 to 22.7 percent greater than
the prescribed dose of 40 Gy (4000 rad).
Discussion
10 CFR 35.32, *Quality Management Program," requires licensees to develop
written procedures to meet five objectives associated with any brachytherapy
dose, including assurance that the prescribed dose is the administered dose.
A necessary part of this is to ensure that the dose rate emitted from an
applicator is correct. If the manufacturer's certificate of calibration or
original activity/dose rate name plate is missing, the licensee should arrange
with a qualified expert to determine the dose rate from the Sr-90 source.
(For additional details, see NRC IN 94-17, NSr-90 Eye Applicators: Submission
of Quality Management Plan, Calibration and Use," dated March 11, 1994.)
Failure to implement the Quality Management Rule and make required reports may
subject a licensee to orders, civil penalties, and notices of violation.
In view of the nature of the cited events, it appears worthwhile to review
some of the properties of Sr-90 eye applicators and the related processes for
decay correction over time. New Sr-90 eye applicators typically contain a
2 gigabecquerel (GBq) [54 millicurie(mCi)] source, exhibiting a surface dose
rate of about 0.50 Gy (50 rad)/sec. The half-life of the parent Sr-90 is
28.5 yrs [maximum beta energy equal to 0.54 mega-electron volts (MeY)], and
the yttrium-90 (Y-90) daughter half-life is 64.2 hrs (beta-max, 2.27 MeV);
therefore, both isotopes are in equilibrium on the eye applicator. Since
Sr-90 and Y-90 are in equilibrium, emissions from both isotopes must be
accounted for in dosimetry calculations.
IN 96-66 December 13, 1996 rate
The dose rate (D,) at a time (t) can be calculated from the initial dose
(De) at the time of the most recent calibration with the following formula:
D = D - (e-^t) (FI)
-Xt
where e, the base of the natural logarithm (2.718), is raised to the powerT. is
and is referred to as the 'decay factor' (df), where -X - -0.693/Tx, the half-life of the isotope, and t is the elapsed time. For Sr-90, TX-28.5 can
years; therefore, X - (0.693)/(28.5 yrs) = 0.0243 yr'. The values for df
after t
be used to determine the fraction of original activity remaining
years. These values can then be used to calculate dose rates by using the
following formula:
D,= Dao df (F2)
The fraction of activity remaining after a given number of years from the
original measurement date is given in Table 1 (Attachment 1).
For example
An eye applicator calibrated by the manufacturer on January 1, 1978, If, delivered
on contact. on
an initial dose rate ( Do) of 0.75 Gy/sec (75 rad/sec)
(in
January 1, 1996, the eye applicator needs to be used, the elapsed time
years) since calibration is 18, and from Table 1, df = 0.646 for Sr-90.
Using formula F2:
D,= bo. df
D18yaM - (0.75 Gy/sec)(0.646)
bigyea - 0.485 Gy/sec
(48.5 rad/sec)
IN 96-66 December 13, 1996 Table I may be extended using formula F1 and the value X - 0.0243 yr' for
Sr-90. Other values of df that need to be evaluated by licensees will need to
be re-calculated by using the appropriate half-life for that isotope.
Alternatively, a semi-logarithmic plot of the above data will yield a straight
line, which may be extended beyond 25 years.
This information notice requires no specific action nor written response. If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate regional office.
Donald A. Cool, D rector
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 E-mail: jxd2@nrc.gov
Emilio M. Garcia, RIV
(510) 975-0239 E-mail: emg@nrc.gov
James A. Smith, NMSS
(301) 415-7904 E-mail: jas4@nrc.gov
Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
42 T7SSI (/4e
Attachment I
IN 96-66 December 13, 1996 Page 1 of I
TABLE 1 FRACTION (EXPRESSED AS DECIMAL) OF ORIGINAL
SR-90 ACTIVITY REMAINING AFTER (t) YEARS
df Years (t) df Years (t) df Years (t) df
Years (t)
0.994 6.5 0.854 12.75 0.734 19 0.63
.25
6.75 0.849 13 0.729 19.25 0.626
.5 0.988
0.982 7 0.844 13.25 0.725 19.5 0.623
.75
0.976 7.25 0.838 13.5 0.72 19.75 0.619
1
0.97 7.5 0.833 13.75 0.716 20 0.615
1.25
0.964 7.75 0.828 14 0.712 20.25 0.611
1.5
0.958 8 0.823 14.25 0.707 20.5 0.608
1.75
0.953 8.25 0.818 14.5 0.703 20.75 0.604
2
0.947 8.5 0.813 14.75 0.699 21 0.6
2.25
0.941 8.75 0.808 15 0.695 21.25 0.597
2.5
0.935 9 0.804 15.25 0.69 21.5 0.593
2.75
0.93 9.25 0.799 15.5 0.686 21.75 0.589
3
0.924 9.5 0.794 15.75 0.682 22 0.586
3.25
9.75 0.789 16 0.678 22.25 0.582
3.5 0.918
10 0.784 16.25 0.674 22.5 0.579
3.75 0.913
10.25 0.78 16.5 0.67 22.75 0.575
4 0.907
0.902 10.5 0.775 16.75 0.666 23 0.572
4.25
0.896 10.75 0.77 17 0.662 23.25 0.568
4.5
11 0.765 17.25 0.658 23.5 0.565
4.75 0.891
11.25 0.761 17.5 0.654 23.75 0.562
5 0.886
11.5 0.756 17.75 0.65 24 0.558
5.25 0.88
0.875 11.75 0.752 18 0.646 24.25 0.555
5.5
0.87 12 0.747 18.25 0.642 24.5 0.551
5.75
0.864 12.25 0.743 18.5 0.638 24.75 0.548
6
0.859 12.5 0.738 18.75 0.634 25 0.545
6.25
Attachment 2 IN 96-66 December 13, 1996 Page 1 of I
UST OF RECENTLY ISSUED
NMSS INFORMATION NOTICES
Information Date of
Notice No. Subject Issuance Issued to
96-63 Potential Safety Issue 12/05196 All U.S. Nuclear Regulatory
Regarding the Shipment Commission licensees
of Fissile Material authorized to possess special
nuclear material in unsealed
quantities greater than a
critical mass
96-57 Incident-Reporting Require- 10/30196 All U.S. Nuclear Regulatory
ments Involving Intakes, Commission licensees
During a 24-Hour Period
that May Cause a Total
Effective Dose Equivalent
in Excess of 0.05 Sv (5 rem)
96-54 Vulnerability of Stainless 10/17/96 All material licensees
Steel to Corrosion When
Sensitized
96-53 Retrofit to Amersham 660 10115/96 All industrial radiography
Posilock Radiography licensees
Camera to Correct Incon- sistency in 10 CFR Part 34 Compatibility
96-52 Cracked Insertion Rods 09/26/96 All U.S. Nuclear Regulatory
on Troxler Model 3400 Commission portable gauge
Series Portable Moisture licensees and vendors
Density Gauges
96-51 Residual Contamination 09/11196 All material licensees
Remaining in Krypton-85 Handling System After
Venting
' >
Attachment 3 IN 96-66 December 13, 1996 Page 1 of I
UST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information Date of
Notice No. Subject Issuance Issued to
96-65 Undetected Accumulation 1211 1/96 All holders of OLs
of Gas in Reactor Coolant or CPs for nuclear
System and Inaccurate power reactors
Reactor Water Level
Indication During Shutdown
96-64 Modifications to Con- 12/10196 All holders of OLs
tainment Blowout Panels or CPs for nuclear
Without Appropriate reactors
Design Controls
96-63 Potential Safety Issue 12/05196 All U.S. Nuclear
Regarding the Shipment Regulatory Commission
of Fissile Material licensees authorized
to possess special
nuclear material in
unsealed quantities
greater than a critical
mass
96-62 Potential Failure of the 11120196 All holders of OLs
Instantaneous Trip Function and CPs for nuclear
of General Electric RMS-9 power plants
Programmers
96-61 Failure of a Main Steam Safety 11/20/96 All holders of OLs or
Valve to Reseat Caused by an CPs for nuclear power
Improperly Installed Release . reactors
Nut
96-60 Potential Common-Mode Post- 11/14/96 All holders of OLs or
Accident Failure of Residual CPs for nuclear power
Heat Removal Heat Exchangers reactors
OL = Operating License
CP = Construction Permit
. December 13, 1996 Table 1 may be extended using formula FH and the value x - 0.0243 yr1 for
Sr-90. Other values of df that need to be evaluated by licensees will need to
be re-calculated by using the appropriate half-life for that isotope.
Alternatively, a semi-logarithmic plot of the above data will yield a straight
line, which may be extended beyond 25 years.
This information notice requires no specific action nor written response. If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate regional office.
Donald A. Cool, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 E-mail: jxd2@nrc.gov
Emilio M. Garcia, RIV
(510) 975-0239 E-mail: emg@nrc.gov
James A. Smith, NMSS
(301) 415-7904 E-mail: jas4enrc.gov
Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Official Record Copy S:\Jsmith\imns5350.JAS
OFC IMAB I E IMAB lIMAB I IMOB I Tech Ed I
KANE JASmith SLMerchant LWCamper o JMPiccone o EKraus o
DATE 1 11/26/96 11/26/96 110/28/96 10/29/96 8/01/96 OFC J IJE OGC I DD/IMNS I D/IMNS I
NAME JLiebermano SATreby o FCCombso DACool
DATE 08/07/96 11/07/96 11/12/96 I 11/29/96
- COWVER E = COVER & Attachment N - NO COPY o- See Previous Concurrence
eIN 96-##
'J November .1996 Table 1 may be extended using formula F1 and the value A = 0.0243 yr" for
Sr-90. Other values of df that need to be evaluated by licensees will need to
be re-calculated by using the appropriate half-life for that isotope.
Alternatively, a semi-logarithmic plot of the above data will yield a straight
line, which may extended beyond 25 years.
This information notice requires no specific action nor written response. If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate regional office.
Donald A. Cool, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 Internet: JXD2@NRC.GOV
Emilio M. Garcia, RIV
(510) 975-0239 Internet: EMG@NRC.GOV
James A. Smith, NMSS
(301) 415-7904 Internet:JAS4@NRC.GOV
Attachments:
1. Table of decay factors
2. List of Recently Issue(d NMSS Information Notices
3. List of Recently Issue(d NRC Information Notices
fffirial Rernrd COnY Svisrnith\imns5350JAS
OFC IMAB lE IMAB lIMAB lIMOB j Tech Ed
NAME JASmi SLM@f@I~nt LWCamper o JMPiccone o EKraus @
DATE it /96 i 10/8/
9 6 10/29/96 8/01/96 OFC OE I OGC DD/IMNS DlIMNS
NAME JLieberman@ SATreby @ FCCombs@ _____ __ _ _l
DATE 08/07/96 11/07/96 11/12/96 ///t11/96
= COVER E = COVER & Attachment N = NO COPY ?--See Previous Concurrence
N 96-Il
-November 91996 This information notice requires no specific action nor written respons . If
you have any questions about the information in this notice, please c tact
one of the technical contacts listed below or the appropriate reglo 1 office.
Donald A. Cool, Director, Division of Industrial and
Medical Nuclear Sa ty
Office of Nuclear terial Safety
and Safeguards
Contacts: Jose M. Diaz-Velez, RI
(404) 331-7438 Internet: JXD2@NRC.GOV
Emilio M. Garcia, RIV
(510) 975-0239 Internet: EMG@NRC.GOV
James A. Smith, NMSS
(301) 415-7904 Internet:JAS4@NRC.GOV
Attachments:
1. Table of decay factors
2. List of Recently Issued NMS Information Notices
3. List of Recently Issued MR Information Notices
Official Record Copy 5: \smitinins5350.JAS
OFC IMAB I E IMAB//1S IMAB I IMOB I Tech E
NAME JASmithm SL erc nt LWCamper o JMPiccone a EKraus o
DATE t//14/96 A/96 10/28/96 10/29/96 8/01/96 OFC OE l OGC DD/IMNS D/IMNS
NAME JLiebermanq/ SATreby o FCCombso DACool
DATE 08/07/9 11/07/96 11/12/96 / /96 C = COVER E M OVER h Attachment N a NO COPY o- See Previous Concurrence
N 96-##
- .
a *-i ovember .1996 D
18year (0.75 Gy/sec)(0.646)
"
blyrs, 0G0.485 Gy/sec
Table 1 may be extended using formula F1 and the value A 0.0243 yr-.
Alternatively, a semi-logarithmic plot of the above dat will yield a straight
line, which may extended beyond 20 years.
This information notice requires no specific actio nor written response. If
you have any questions about the information in t s notice, please contact
one of the technical contacts listed below or t appropriate regional office.
Donald . Cool. Director
Divis on of Industrial and
M ical Nuclear Safety
Ofice of Nuclear Material Safety
and Safeguards
Contacts: Jose M. Diaz-Velez,
(404) 331-7438 Internet:JMD2@NRC. V
Emilio M. Garci , RIV
(510) 975-0239/
Internet:EM C.GOV
James A. S ,thNMSS
(301) 415- 904 Internet- AS4@NRC.GOV
Attachments:
1. List of Recent y Issued NMSS Information Notices
2. List of Rece ly Issued NRC Information Notices
Official Recordo S:\jsmith\imns5350.JAS
OFC
NAME
DATE /
/1*196 E
I IMAB
le/6///96 ant
jI I
LWCamper o
10/28/96 II MOB
JMPiccone
10/29/96
@
Techi Ed
EKraus o
8/01/96 OFC/ OE I OGC DD/IMNS D/IMNS l
AM JLiebermano SATreby o FCCombso DACool
D0/07/96 11/07/96 11/12/96 / /96
,COVER E = COVER & Attachment N = NO COPY @- See Previous Concurrence
N 96-ft
<iovember ,1996 D (0.75 Gy/sec)(0.646)
.0.485 Gy/sec
1 Table 1 may be etended using formula F1 and the value X - 0.0243 yr .
Alternatively, a mi-logarithmic plot of the above data will yield a straight
line, which may ext nded beyond 20 years.
This information noti requires no specific action nor written response. If
you have any questions bout the information inthis notice, please contact
(one of) the technical c tact(s) listed below or the appropriate regional
office.
Donald A. Cool, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 Internet:JMD2@NRC.GOY
Emilio M. Garcia, RIV
(510) 975-0239 Internet:EMG@NRC.GOV
James A. Smith, NMSS
(301) 415-7904 Internet:JAS4@NRC.GOV
Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Official Record Copy S:\Jsmith\imns5350.JAS \
OFC qIMABiLW B IM4AB - l
IMOB E\Tech Ed
NAME JASm1i SL chant LWCamper a JMPiccone c EKraus o
DATE I I 1/96 _ / j 10/28/96 10/29/96 8/01/96 OFC OE OGC DD/IMNS D/IMNS
NAME JLiebermano SATreby a F(Cm DACool
DATE 08/07/96 11/07/96 / /96 C a COVER E a CUVLK & Attacnment N = mU LUr1'u- aee rrevmuUs IA0ICUIIrCLM.
,N96-##
' "-'-6ctober ,1996 ble8.. - (0.75 Gy/sec)(0.646)
l 0.4 y/sec
Table 1 may be extended using fo ula F1 and the value X - 0.0243 yre.
Alternatively, a semi-logarithmic lot of the above data will yield a straight
line, which may extended beyond 20 ars.
This information notice requires no sp ific action nor written response. If
you have any questions about the infrma ion inthis notice, please contact
(one of) the technical contact(s) listed elow or the appropriate regional
office.
Donald A. -ool, Director
Division o Industrial and
Medical Ntclear Safety
Office of N clear Material Safety
and Safegu rds
Contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 Internet:JMD2@NRC. GOY
Emilio M. Garcia, RIV
(510) 975-0239 Internet:EMG@NRC.GOV
James A. Smith, NMSS
(301) 415-7904 Internet:JAS4@NRC .GOV
Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Official Record Copy S:\Jsmithi\mns5350.JAS \
OFCIMAB AB IMAB I l IMOB l \l,TechEdl
NAME JASai R SUM nt LWCamper a JMPiccone o EKraus o
DATE / -J/ 10/28/96 10/29/96 8/01/96 OFC OE DD/IMNS D/IMNS
KANE JLiebermano Sireb NIL FCCombs DACool
DATE 08/07/96 l/ /1/96 / /96 / /96 aCOVER E a COVER & Attachment K = ND COPY o- See Previous Concurrence \
C,6 I < ~N96-#t
4 October ,1996 We have Dlew. - (0.75 Gy/sec)(0.646)
Table I may be extended using formula FH and the value X - 0.0243 yr1 .
Alternatively, a semi-icgarithmic plot of the above data will yield a straight
line, which may extended be~yond 20 years.
This information notice requires no specific action nor written response. If
you have any questions about the information in this notice, please contact
(one of) the technical contact(s) listed below or the appropriate regional
office.
Donald A. Cool, Director
Division of Industrial and
Medical Nuclear Safety
Office cf Nuclear Material Safety
and Safrguards
Contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 Internet:JMD2@NRC.60V
Emilio M. Garcia, RIV
(510) 975-0239 Internet:EMG@NRC.GOY
James A. Smith, NMSS
(301) 415-7904 Internet:JAS4@NRC.GOV
Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Official Record CODY SA:smithkimtns535GJAS
OFC IMAB E IMAB Tech
NAME JASmi S rchant C rer on EKraus o
DATE It/1 /96 /96 96 /09 /96 8/01/96 OFC OE lOGC lDD/IMNS l D/IMNS l~
KANE JLiebermano SATreby FCCombs DACool
DATE 08/07/96 / /96 I /96 / /96
- COVER E a COVER & Attachment N = NO COPY e- See Previous Concurrence
A '
IN 96-##
August ,1996 This informat n not1ce requires no specific action nor written response. If
you have any qu tions about the information in this notice, please contact
(one of) the techn cal contact(s) listed below or the appropriate regional
office.
Donald A. Cool, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Contacts: Jose M. Diaz-Velez, RII
(404) 331-7438 Emilio M. Garcia, RIV
(510) 975-0239 James A. Smith, NMSS
(301) 415-7904 Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Official Record Copy G:\imns5350.JAS , )
OFC IMABl E IlTech
OGC Ed
NAME JASmi'W per SATreby EKraus a
DATE *in /96 __ /________ \___96 / /96 8/01/96 OFC \ IlI DD/IMNS l D/IMNS l
NAME Q jeerman FCCombs DACool
DATE ___9_
- w COVER
/ /96
'E i. COVER & Attachment N = NO COPY o- See Previous Concurrence