Information Notice 1996-66, Recent Misadministrations Caused by Incorrect Calibrations of Strontium-90 Eye Applicators

Recent Misadministrations Caused by Incorrect Calibrations of Strontium-90 Eye Applicators

ML031050494
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	12/13/1996
From:	Cool D A NRC/NMSS/IMNS
To:
References
IN-96-066, NUDOCS 9612090360
Download: ML031050494 (15)

UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D.C. 20555December 13, 1996NRC INFORMATION NOTICE 96-66: RECENT MISADMINISTRATIONS CAUSED BYINCORRECT CALIBRATIONS OF STRONTIUM-90EYE APPLICATORS

Addressees

All U.S. Nuclear Regulatory Commission Medical Use Licensees authorized to usestrontium-90 (Sr-90) eye applicators.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this informationnotice to alert addressees to recent misadministrations caused by incorrectsource strength determinations of Sr-90 eye applicators. It is expected thatrecipients will review the information for applicability to their facilitiesand 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 CircumstancesThe primary causes of two recent events have been problems with calibrationand calculation of the dose rates from Sr-90 applicators. As a result, theadministered doses were not within 20 percent of the prescribed dose.Case 1. In October 1995, during an inspection of a licensee authorized to usea Sr-90 eye applicator in Mayag~ez, Puerto Rico, it was determined that thecalibration record for the licensee's Sr-90 eye applicator was missing. Aprevious owner of the source lost the original calibration certificate, andhis medical physics consultant performed a check of the source strength. Thischeck was performed with an inappropriate measurement instrument and resultedin an incorrect determination of the source strength as 0.24 Gray (Gy)/sec 0(24 rad/sec). The licensee obtained the source in 1994 and relied on theerroneous source strength determination during treatments. Also, the sourcehad not been decay-corrected by either owner since 1990. NRC urged thelicensee to have the eye applicator recalibrated and to be instructed in the D Fc2proper method to calculate the decay of the source.The licensee subsequently had the eye applicator recalibrated by the NationalInstitute of Standards and Technology. The resultant recalibration revealed adose rate of 0.53 Gray (53 rad)/sec rather than the 0.24 Gy (24 rad)/sec usedby the licensee. The licensee had prescribed a total dose of between 10 to25 Gy (1000 to 2500 rad) for approximately9-0709036 f arr&0 C. Dr Ilt, 2a IN 96-66December 13, 1996 0 patients, but actually administered about twice this amount. An NRCmedical consultant has reviewed the cases and has recommended that thepatients be evaluated for any adverse effects.Case 2. In November 1995, while reviewing treatment records during a routineNRC inspection of a licensee authorized to use a Sr-90 eye applicator inHonolulu, Hawaii, an NRC inspector determined that the licensee hadincorrectly calculated the decay of the strength of a Sr-90 eye applicator andsubsequently delivered doses 20 percent over the prescribed doses to 16patients. The root cause of this event was the licensee improperlycalculating the decay of the Sr-90 source. Specifically, the licenseelinearly decayed the strength of the source instead of logarithmicallydecaying the source strength of the eye applicator. Before May 1995, atechnologist had correctly calculated the decay of the source; however, whenthis technologist left, the physician incorrectly calculated the source decaybased on a linear decay from the previous calculations. In addition, theincorrect half-life of Sr-90 was used in the calculation.Following a correct determination of the source strength, the licenseedetermined that 17 misadministrations involving 16 patients occurred, fromMay 6, 1995 to November 16, 1995, including one patient who was treated onboth eyes. The delivered doses range from 21.1 to 22.7 percent greater thanthe prescribed dose of 40 Gy (4000 rad).Discussion10 CFR 35.32, *Quality Management Program," requires licensees to developwritten procedures to meet five objectives associated with any brachytherapydose, including assurance that the prescribed dose is the administered dose.A necessary part of this is to ensure that the dose rate emitted from anapplicator is correct. If the manufacturer's certificate of calibration ororiginal activity/dose rate name plate is missing, the licensee should arrangewith 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: Submissionof Quality Management Plan, Calibration and Use," dated March 11, 1994.)Failure to implement the Quality Management Rule and make required reports maysubject a licensee to orders, civil penalties, and notices of violation.In view of the nature of the cited events, it appears worthwhile to reviewsome of the properties of Sr-90 eye applicators and the related processes fordecay correction over time. New Sr-90 eye applicators typically contain a2 gigabecquerel (GBq) [54 millicurie(mCi)] source, exhibiting a surface doserate of about 0.50 Gy (50 rad)/sec. The half-life of the parent Sr-90 is28.5 yrs [maximum beta energy equal to 0.54 mega-electron volts (MeY)], andthe 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. SinceSr-90 and Y-90 are in equilibrium, emissions from both isotopes must beaccounted for in dosimetry calculation IN 96-66December 13, 1996 The dose rate (D,) at a time (t) can be calculated from the initial dose rate(De) at the time of the most recent calibration with the following formula:D = D -(e-^t) (FI)where e, the base of the natural logarithm (2.718), is raised to the power -Xtand is referred to as the 'decay factor' (df), where -X --0.693/Tx, T. isthe half-life of the isotope, and t is the elapsed time. For Sr-90, TX-28.5years; therefore, X -(0.693)/(28.5 yrs) = 0.0243 yr'. The values for df canbe used to determine the fraction of original activity remaining after tyears. These values can then be used to calculate dose rates by using thefollowing formula:D,= Dao df (F2)The fraction of activity remaining after a given number of years from theoriginal measurement date is given in Table 1 (Attachment 1).For exampleAn eye applicator calibrated by the manufacturer on January 1, 1978, deliveredan initial dose rate ( Do) of 0.75 Gy/sec (75 rad/sec) on contact. If, onJanuary 1, 1996, the eye applicator needs to be used, the elapsed time (inyears) since calibration is 18, and from Table 1, df = 0.646 for Sr-90.Using formula F2:D, = bo. dfD18yaM -(0.75 Gy/sec)(0.646)bigyea -0.485 Gy/sec(48.5 rad/sec)

IN 96-66December 13, 1996 Table I may be extended using formula F1 and the value X -0.0243 yr' forSr-90. Other values of df that need to be evaluated by licensees will need tobe re-calculated by using the appropriate half-life for that isotope.Alternatively, a semi-logarithmic plot of the above data will yield a straightline, which may be extended beyond 25 years.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.Donald A. Cool, D rectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts: Jose M. Diaz-Velez, RII(404) 331-7438E-mail: jxd2@nrc.govEmilio M. Garcia, RIV(510) 975-0239E-mail: emg@nrc.govJames A. Smith, NMSS(301) 415-7904E-mail: jas4@nrc.gov

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information Notices42 T7SS I (/4e Attachment IIN 96-66December 13, 1996Page 1 of ITABLE 1FRACTION (EXPRESSED AS DECIMAL) OF ORIGINALSR-90 ACTIVITY REMAINING AFTER (t) YEARSYears (t) df Years (t) df Years (t) df Years (t) df.25 0.994 6.5 0.854 12.75 0.734 19 0.63.5 0.988 6.75 0.849 13 0.729 19.25 0.626.75 0.982 7 0.844 13.25 0.725 19.5 0.6231 0.976 7.25 0.838 13.5 0.72 19.75 0.6191.25 0.97 7.5 0.833 13.75 0.716 20 0.6151.5 0.964 7.75 0.828 14 0.712 20.25 0.6111.75 0.958 8 0.823 14.25 0.707 20.5 0.6082 0.953 8.25 0.818 14.5 0.703 20.75 0.6042.25 0.947 8.5 0.813 14.75 0.699 21 0.62.5 0.941 8.75 0.808 15 0.695 21.25 0.5972.75 0.935 9 0.804 15.25 0.69 21.5 0.5933 0.93 9.25 0.799 15.5 0.686 21.75 0.5893.25 0.924 9.5 0.794 15.75 0.682 22 0.5863.5 0.918 9.75 0.789 16 0.678 22.25 0.5823.75 0.913 10 0.784 16.25 0.674 22.5 0.5794 0.907 10.25 0.78 16.5 0.67 22.75 0.5754.25 0.902 10.5 0.775 16.75 0.666 23 0.5724.5 0.896 10.75 0.77 17 0.662 23.25 0.5684.75 0.891 11 0.765 17.25 0.658 23.5 0.5655 0.886 11.25 0.761 17.5 0.654 23.75 0.5625.25 0.88 11.5 0.756 17.75 0.65 24 0.5585.5 0.875 11.75 0.752 18 0.646 24.25 0.5555.75 0.87 12 0.747 18.25 0.642 24.5 0.5516 0.864 12.25 0.743 18.5 0.638 24.75 0.5486.25 0.859 12.5 0.738 18.75 0.634 25 0.545 Attachment 2IN 96-66December 13, 1996Page 1 of IUST OF RECENTLY ISSUEDNMSS INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-6396-5796-5496-5396-5296-51Potential Safety IssueRegarding the Shipmentof Fissile MaterialIncident-Reporting Require-ments Involving Intakes,During a 24-Hour Periodthat May Cause a TotalEffective Dose Equivalentin Excess of 0.05 Sv (5 rem)Vulnerability of StainlessSteel to Corrosion WhenSensitizedRetrofit to Amersham 660Posilock RadiographyCamera to Correct Incon-sistency in 10 CFR Part 34CompatibilityCracked Insertion Rodson Troxler Model 3400Series Portable MoistureDensity GaugesResidual ContaminationRemaining in Krypton-85Handling System AfterVenting12/0519610/3019610/17/9610115/9609/26/9609/11196All U.S. Nuclear RegulatoryCommission licenseesauthorized to possess specialnuclear material in unsealedquantities greater than acritical massAll U.S. Nuclear RegulatoryCommission licenseesAll material licenseesAll industrial radiographylicenseesAll U.S. Nuclear RegulatoryCommission portable gaugelicensees and vendorsAll material licensees

' >Attachment 3IN 96-66December 13, 1996Page 1 of IUST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-6596-6496-6396-6296-6196-60Undetected Accumulationof Gas in Reactor CoolantSystem and InaccurateReactor Water LevelIndication During ShutdownModifications to Con-tainment Blowout PanelsWithout AppropriateDesign ControlsPotential Safety IssueRegarding the Shipmentof Fissile MaterialPotential Failure of theInstantaneous Trip Functionof General Electric RMS-9ProgrammersFailure of a Main Steam SafetyValve to Reseat Caused by anImproperly Installed ReleaseNutPotential Common-Mode Post-Accident Failure of ResidualHeat Removal Heat Exchangers1211 1/9612/1019612/051961112019611/20/9611/14/96All holders of OLsor CPs for nuclearpower reactorsAll holders of OLsor CPs for nuclearreactorsAll U.S. NuclearRegulatory Commissionlicensees authorizedto possess specialnuclear material inunsealed quantitiesgreater than a criticalmassAll holders of OLsand CPs for nuclearpower plantsAll holders of OLs orCPs for nuclear power.reactorsAll holders of OLs orCPs for nuclear powerreactorsOL = Operating LicenseCP = Construction Permit IN 96-66.December 13, 996Table 1 may be extended using formula FH and the value x -0.0243 yr1 forSr-90. Other values of df that need to be evaluated by licensees will need tobe re-calculated by using the appropriate half-life for that isotope.Alternatively, a semi-logarithmic plot of the above data will yield a straightline, which may be extended beyond 25 years.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsTechnical contacts:Jose M. Diaz-Velez, RII(404) 331-7438E-mail: jxd2@nrc.govEmilio M. Garcia, RIV(510) 975-0239E-mail: emg@nrc.govJames A. Smith, NMSS(301) 415-7904E-mail: jas4enrc.gov

Attachments:

1. List of Recently2. List of RecentlyIssued NMSS Information NoticesIssued NRC Information NoticesOfficial Record Copy S:\Jsmith\imns5350.JASOFC IMAB I E IMAB lIMAB I IMOB I Tech Ed IKANE JASmith SLMerchant LWCamper o JMPiccone o EKraus oDATE 1 11/26/96 11/26/96 1 10/28/96 10/29/96 8/01/96OFC J JE I OGC I DD/IMNS I D/IMNS INAME JLiebermano SATreby o FCCombso DACoolDATE 08/07/96 1 1/07/96 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" forSr-90. Other values of df that need to be evaluated by licensees will need tobe re-calculated by using the appropriate half-life for that isotope.Alternatively, a semi-logarithmic plot of the above data will yield a straightline, which may extended beyond 25 years.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate regional office.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsContacts:Jose M. Diaz-Velez, RII(404) 331-7438Internet: JXD2@NRC.GOVEmilio M. Garcia, RIV(510) 975-0239Internet: EMG@NRC.GOVJames A. Smith, NMSS(301) 415-7904Internet:JAS4@NRC.GOV

Attachments:

1. Table of decay factors2. List of Recently Issue(3. List of Recently Issue(fffirial Rernrd COnY Svisrd NMSS Information Noticesd NRC Information Noticesnith\imns5350JASOFC IMAB lE IMAB lIMAB lIMOB j Tech EdNAME JASmi SLM@f@I~nt LWCamper o JMPiccone o EKraus @DATE it /96 i 10/8/ 9 6 10/29/96 8/01/96OFC OE I OGC DD/IMNS DlIMNSNAME JLieberman@ SATreby @ FCCombs@ _____ __ _ _lDATE 08/07/96 11/07/96 11/12/96 ///t11/96= COVER E = COVER & Attachment N = NO COPY ?--See Previous Concurrence N 96-Il-N ovember 91996 This information notice requires no specific action nor written respons .Ifyou have any questions about the information in this notice, please c tactone of the technical contacts listed below or the appropriate reglo 1 office.Donald A. Cool, Director,Division of Industrial andMedical Nuclear Sa tyOffice of Nuclear terial Safetyand SafeguardsContacts: Jose M. Diaz-Velez, RI(404) 331-7438Internet: JXD2@NRC.GOVEmilio M. Garcia, RIV(510) 975-0239Internet: EMG@NRC.GOVJames A. Smith, NMSS(301) 415-7904Internet:JAS4@NRC.GOV

Attachments:

1. Table of decay factors2. List of Recently Issued NMS Information Notices3. List of Recently Issued MR Information NoticesOfficial Record Copy 5: \smitinins5350.JASOFC IMAB I E IMAB//1S IMAB I IMOB I Tech ENAME JASmithm SL e rc nt LWCamper o JMPiccone a EKraus oDATE t/ /14/96 A/ 96 10/28/96 10/29/96 8/01/96OFC OE l OGC DD/IMNS D/IMNSNAME JLiebermanq/ SATreby o FCCombso DACoolDATE 08/07/9 11/07/96 11/12/96 / /96C = COVER E M OVER h Attachment N a NO COPY o- See Previous Concurrence

. N 96-##a *-i ovember .1996 D18year " (0.75 Gy/sec)(0.646)blyrs, 0G 0.485 Gy/secTable 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 straightline, which may extended beyond 20 years.This information notice requires no specific actio nor written response. Ifyou have any questions about the information in t s notice, please contactone of the technical contacts listed below or t appropriate regional office.Donald .Cool. DirectorDivis on of Industrial andM ical Nuclear SafetyOfice of Nuclear Material Safetyand SafeguardsContacts

Jose M. Diaz-Velez,(404) 331-7438Internet:JMD2@NRC. VEmilio M. Garci , RIV(510) 975-0239/Internet:EM C.GOVJames A. S ,th NMSS(301) 415- 904Internet- AS4@NRC.GOV

Attachments:

1. List of Recent y Issued NMSS Information Notices2. List of Rece ly Issued NRC Information NoticesOfficial Recordo S:\jsmith\imns5350.JASOFC IMA E IMAB jI I I MOB I Tech Ed iNAME I ant LWCamper o JMPiccone @ EKraus oDATE / /1196 le /6///96 10/28/96 10/29/96 8/01/96OFC / OE I OGC DD/IMNS D/IMNS lAM JLiebermano SATreby o FCCombso DACoolD0/07/96 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/secTable 1 may be etended using formula F1 and the value X -0.0243 yr1.Alternatively, a mi-logarithmic plot of the above data will yield a straightline, which may ext nded beyond 20 years.This information noti requires no specific action nor written response. Ifyou have any questions bout the information in this notice, please contact(one of) the technical c tact(s) listed below or the appropriate regionaloffice.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsContacts: Jose M. Diaz-Velez, RII(404) 331-7438Internet:JMD2@NRC.GOYEmilio M. Garcia, RIV(510) 975-0239Internet:EMG@NRC.GOVJames A. Smith, NMSS(301) 415-7904Internet:JAS4@NRC.GOV

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information NoticesOfficial Record Copy S:\Jsmith\imns5350.JAS \OFC qIMABiLW B IM4AB -IMOB l E\Tech EdNAME JASm1 i SL chant LWCamper a JMPiccone c EKraus oDATE I I 1/96 _ / j 10/28/96 10/29/96 8/01/96OFC OE OGC DD/IMNS D/IMNSNAME JLiebermano SATreby a F (Cm DACoolDATE 08/07/96 11/07/96 / /96C a COVER E a CUVLK & Attacnment N = mU LUr1'u- aee rrevmuUs IA0ICUIIrCL ,N 96-##' "-'-6ctober ,1996 ble8.. -(0.75 Gy/sec)(0.646)l 0.4 y/secTable 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 straightline, which may extended beyond 20 ars.This information notice requires no sp ific action nor written response. Ifyou have any questions about the in frma ion in this notice, please contact(one of) the technical contact(s) listed elow or the appropriate regionaloffice.Donald A. -ool, DirectorDivision o Industrial andMedical Ntclear SafetyOffice of N clear Material Safetyand Safegu rdsContacts: Jose M. Diaz-Velez, RII(404) 331-7438Internet:JMD2@NRC. GOYEmilio M. Garcia, RIV(510) 975-0239Internet:EMG@NRC.GOVJames A. Smith, NMSS(301) 415-7904Internet:JAS4@NRC .GOV

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information NoticesOfficial Record Copy S:\Jsmithi\mns5350.JAS \OFC IMAB AB IMAB I l IMOB l \l,Tech EdlNAME JASai R SUM nt LWCamper a JMPiccone o EKraus oDATE / -J/ 10/28/96 10/29/96 8/01/96OFC OE DD/IMNS D/IMNSKANE JLiebermano S ireb NIL FCCombs DACoolDATE 08/07/96 l/ /1/96 / /96 / /96aCOVER E a COVER & Attachment K = ND COPY o- See Previous Concurrence \

C, 6 I< ~N 96-#t4 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 straightline, which may extended be~yond 20 years.This information notice requires no specific action nor written response. Ifyou have any questions about the information in this notice, please contact(one of) the technical contact(s) listed below or the appropriate regionaloffice.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice cf Nuclear Materialand SafrguardsSafetyContacts:Jose M. Diaz-Velez, RII(404) 331-7438Internet:JMD2@NRC.60VEmilio M. Garcia, RIV(510) 975-0239Internet:EMG@NRC.GOYJames A. Smith, NMSS(301) 415-7904Internet:JAS4@NRC.GOV

Attachments:

1. List2. ListOfficialof Recentlyof RecentlyRecord CODYIssued NMSS Information NoticesIssued NRC Information NoticesSA:smithkimtns535GJASOFC IMAB E IMAB TechNAME JASmi S on rchant C rer EKraus oDATE It /1 /96 /96 96 /09 /96 8/01/96OFC OE lOGC lDD/IMNS l D/IMNS l~KANE JLiebermano SATreby FCCombs DACoolDATE 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. Ifyou have any qu tions about the information in this notice, please contact(one of) the techn cal contact(s) listed below or the appropriate regionaloffice.Donald A. Cool, DirectorDivision of Industrial andMedical Nuclear SafetyOffice of Nuclear Material Safetyand SafeguardsContacts: Jose M. Diaz-Velez, RII(404) 331-7438Emilio M. Garcia, RIV(510) 975-0239James A. Smith, NMSS(301) 415-7904

Attachments:

1. List of Recently Issued NMSS Information Notices2. List of Recently Issued NRC Information NoticesOfficial Record Copy G:\imns5350.JAS , )OFC IMAB l E I OGC lTech EdNAME JASmi'W per SATreby EKraus aDATE *in /96 __ /________ \___96 / /96 8/01/96OFC \ lI I DD/IMNS l D/IMNS lNAME Q jeerman FCCombs DACoolDATE ___9_ / /96: w COVER 'E i. COVER & Attachment N = NO COPY o- See Previous Concurrence