ML20133E824

Sealed Source and Device Newsletter.Number 96-2

ML20133E824
Person / Time
Issue date:	09/30/1996
From:	NRC
To:
References
NUREG-BR-0177, NUREG-BR-0177-N96-2, NUREG-BR-177, NUREG-BR-177-N96-2, NUDOCS 9701130170
Download: ML20133E824 (7)

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4 Sealed Source & Device Newsletter i

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,e s,- U.S. Nuclear Courtesy of the NUREGIBR-0171 1 Regulatory i Sealed Source No. 96-2

.....) Commission Safety Section September 1996 With technology constantly changing and the need to protect public health and safety, it is imperative that communications between the U.S. Nuclear Regulatory Commission (NRC) and Agreement State programs and also between these regulatory authorities and users of radioactive sealed sources and devices be open and cooperative. The NRC Sealed Source Safety Section (SSSS) is providing this newsletter to promote such communications.

TECHNICAL ISSUES labeling, source location, and how the de-i vice is assembled.

FREQUENTLY ASKED QUESTIONS e A complete or adequate description of the AND ANSWERS applicants Quality Assurance (Q A)and/or Quality Control (QC) program. l Q: What are the most common deficiencies in Scaled Source and Device (SS&D) applications e Identification of a scaled source by the ven-for safety evaluation? dors product code or alternate designation rather then as listed on a registration A: Historically, the most common areas missed for certificate.

initial applications sent to NRC include the

'" Q: Does BEBIG 1rade, Inc. have registration cer-8' tificates for its sealed sources?

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• Complete or adequate dose assessments A: Yes, BEBIG Trade, Inc. has sealed sources reg-i demonstrating compliance with the safety istered on Illinois-issued certificates of registra-cnteria, as defined in the regulations for tion numbers lie.103-S-101-S, -102-S, -103-S, 4

certam types of products-for example, and -107-S.

' consumer products or products intended for use by generallicensees.

It should be noted that the State has included several very important reviewer notes in these certificates.

• Results of testing of products or complete For example, BEBIG does not provide any installa-j historical use data to demonstrate the ef- tion, disposal, or leak testing services for its sources, fectiveness of containment under both and users of the sources must have a QA program for normal and likely accidental conditions of initial receipt and inspection. BEBIG performs only use. manufacturing QA/QC for its sources. Persons li-censing the use of BEBIG sources should ensure they e A clear depiction or description of source read and understand the registration sheets fully so J

security and containment within the that appropriate user requirements may be met be-device. fore the license is issued. Questions about these cer-tificates should be directed to the State.

• Drawings or descriptions sufficient to clearly demonstrate the construction of the Q: How do I determine if a product is registered or j device, including materials of construction, needs to be registered? p i i .

9701130170 960930 PDR NUREG BR-0177 R PDR

A: Policy and Guidance Directive (P&GD) 84-22, ISSUANCE OF RADIOGRAPHY Revision 1, What Source and Device Designs Require An Evaluation, provides the conditions ASSOCIATED EQUIPMENT  !

under which a safety evaluation is and is not re- REGISTRATION CERTIFICATE quired before licensed use of a product may be authorized. For commercial products requiring In accordance with the Radiography Equipment an evaluation, a registration certificate is Rule, all associated equipment used with radiography devices must meet the requirements of 10 CFR created that summarizes the evaluation. A reg-Ibrt 34 before use.The SSSS has completed the eval-istration certificate is typically created for cus-uation of the first request tolist associated equipment )

tom products, as well. 'Ib determine if a product is registered, all one would need to do is refer to in a separate registration certificate. The request in-cluded three series of Amersham generic col'hnators the registration certificate for the product.

for use with radiography equipment. The collimators d are described under registration certificate NR-Persons wishing to use products under their li. 0628-A-135-S.The letter A in the certificate number cense are responsible for identifying the product refers to associated equipment for use with radiogra- d by model number and manufacturer, as regis. phy devices and the certificate specifically describes tered, in their application.The information pro- how the collimators may be used. The A convention ,

vided by the applicant may not correspond to a will be used for all registration certificates issued registered product either because it was not pro- solely for associated equipment. Refer to the registra-

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vided as registered or the product is not regis. tion certificate for additional details concerning th ese tered. If the applican: has not identified the collimators, product as registered, the applicant should con-tact the manufacturer for the appropriate means to identify the product for licensing. If NORDION INTERNATIONAL MODEL I the devtce is not registered, the hcense reviewer C-337 SOURCE ASSEMBlX I must determine if a safety evaluation must be APPROVED ,

performed in accordance with P&GD 84-22. If .

an evaluation is needed, the applicant or the dis- Registration certificate NR-220-S-111-S has been ts-tributor of the product may provide the informa- sued for the Nordion hiodel C-337 radiography tion necessary for the evaluation. source assembly. The C-337 has been approved for use in the SPEC Model C-1 source changer and the Amersham Model 660 Series radiography camera.

The most up-to-date information concerning regis- De source and camera pair have been demonstrated tered products and registration certificates is the reg- to meet the requirements of Section 34.20,10 CFR istration certificate catalogue. NRC and many Agree- Ihrt 34, when used in the 660 Series camera. This in-ment State offices maintain copies of all registration formation will soon be available on the SSD BBS in certificates issued by NRC and the Agreement States. updated RADXREF and SS&D Registry program In addition, NRC has compiled a database of the in- databases.

formation contained on the first page of each certifi-cate as the SS& D Registry search program.The regis-try search program is not intended to be a NORDION INTERNATIONAL ISSUES replacement for the catalogue, but, rather a search A USER BULLETIN FOR THEIR tool to help reviewers in finding the hardcopy MODEL GC-220 GAMMA certificates. IRRADIATORS 1

Persons in Agreement States may obtain copies of Nordion International issued a service bulletin on registration certificates either from their State regu. Y ' ' *# '" 8t

• • " U" ""#"."podel

'" # GC-220 a gam-usen c

latory authority, the State regulatory authority that .

created the certificate, or from Kim Randall at (301) f these devices to the recommendations in the new 415-7857* Internatonal Atomic Energy Agency (IAEA) Safety Series 115. His document recommends an annual maximum dose equivalent limit of 1 mSv (100 mrem)

P&GD 84-22 and the SS& D Registry program may be for non-radiation workers and 20 mSv (2000 mrem) downloaded from the SSD Bulletin Board System for radiation workers.

(BBS). Refer to the 96-lissue of the SS&DNewsletter for more information on the SSD BBS or see the ar- Nordions bulletin further points out that the Model ticle on the SSD BBS later in this issue. GC-220 gamma irradiators were designed and 2

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constructed based,in part, on an older American Na- with the requestors to exhaust all other tional S tandards Instit ute (ANSI) standard which rec- available options.

ommended maximum annual dose equivalent limits of 5 mSv(500) mrem for non radiation workers and 50

• DOE is considering an AmBe recycle mSv (5000 mrem) for radiation workers. Nordion in- Program at Los Alamos, similar to their dicates that users of Model OC-220 gamma irradia- current Plutonium: Beryllium recycle tors who wish to follow the IAEA recommendations program.

will, therefore, need to take appropriate precautions in accordance with the ALARA philosophy when working around these devices. SENTINEL RETROFIT OF BUMPERS ON MODEL 660 RADIOORAPHY CAMERAS INFORMATION NOTICE 96-35 PUBLISHED Recent testing performed by an independent labora. )

tory indicated that Sentinel (formerly Amersham)

Information Notice (IN)96-35, Failure of Safety Sys- m del 660 cameras with Posilok assemblics are sus-tems on Self Shielded Irradiators Because ofInade- ceptible to breakage of the lock slide when subjected 4 quate Maintenance and ' Raining, was published to the ANSI N432-1980 horizontal shock test. Fol.

June 11,1996.'Dris IN was published to remind users I wing the testing, Sentinelinvestigated the results of self-shielded irradiators of the importance of regu- and determined that specific, repeated, horizontal lar and periodic maintenance and training for the ir- shocks to one of the bumpers on the rear plate of the radiators. Two examples are cited where additional camera will eventually cause breakage of the lock maintenance and/or training may have prevented slide. Sentinel indicated that this type of breakage has needless personnel exppsures. n t been reported in the field,it is unlikely that an im-pact during field use would result in breakage of the lock slide, and that if breakage did occur, return of the NRC/ DOE ASSISTANCE PROORAM- source to the fully shielded position and return of the UPDATE lock slide to the secured position will not be pre-vented. However, further source exposure would be U.S. Department of Energy (DOE)and NRC current Prevented, so the failure would not present a radio-l actions under this program: logical safety concern.

e DOE has reviewed the proposed Memo- 'Ib prevent occurrence of this type of breakage during randum of Understanding (MOU) in- use, Sentinel will be issuing a bulletm and a retrofit tended to codify and formalize the program kit to all known owners of the 660 Posilok cameras.

and has returned comments and concerns retr Et kit contains replacement bumpers that to NRC. DOE and NRC staff are working have been reinforced to prevent breakage of the lock to redraft the MOU, with the comments slide if subjected to repeated hori7ontal shocks.

and concerns addressed.

BERTHOLD SYSTEMS INC.10 CFR -

• DOE successfully resolved a State of Illi- PART 21 REPORT OF DEFECT IN nois request for assistance with the retriev- SOME LB 7400 SERIES al of several americium 241: beryllium DEVICES-UPDATE (AmBe) well logging sources.

Berthold SystemsIncorporated, Apgee Corporation, e DOE is working to resolve a request for as- and EG&G Berthold have completed theirinvestiga.

sistance in the management of twoirradia- tion of a Part 21 defect of the shutter mechanisms of tors, each containing approximately 7.77 some Berthold model LB 7440 and LB 7442 devices.

TBq (210 Ci) Cs-137, possessed by non- Bertholds corrective action consisted of notifying the licensed, private high schools. potentially affected licensees, having the licensees test for the defect, replacing all devices with the de-e DOE and NRC staff met to discuss several fect, and changing the manufacturing process that issues concerning the current program and caused the defect. Of the 400 potentially affected de-its future. vices, 50 (12.5 percent) were reported by the users as exhibiting problems with shutter operation. Berthold e NRC staff is currently reviewing several indicated that only 30 of these (7.5 percent) required other requests for assistr.nce and working replacement because of the defect.

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Ilerthold indicated that the Iart 21 investigation is tion of the product about mechanisms that may break closed, but committed to continuing to monitor cus-down corrosion protection properties of construction tomer service calls for possible future occurrences of materials, causing the material to become vulnerable the defect with the remaining 370 devices.

to corrosion. Some areas to consider include inter.

granular corrosion and pitting corrosion.

SPECIAL TOPICS ne following paragraphs provide a discussion Sensi-tization and Intergranular corrosion of 316L stainless COYtROSION OF STAINLESS STEELS Although stainless steels are considered as having ex- 8'"3I'I###I88 cellent corrosion resistance, they are susceptible to corrosion. Steels can be protected against corrosion Normal 316L stainless steel has chromium atoms dis-by alloying them with protective elements such as persed throughout their crystalline structure. 316L contains 0.03 percent carbon, that combines with the chromium. Chromium forms a protective film on the e surface on the steel, protecting the underlying metal chromium atoms to form chromium carbides. If the from corrosion. For example 316L stainless steel, metal is heated to a temperature within the critical which is considered to have high corrosion resistance, temperature range of 425'C to 850*C (797*F to contains 17 percent chromium. However, once this 1562*F) and then slowly cooled, the chromium car-protective barrier is broken, the material becomes bides can precipitate at the grain boundaries. As a re-sult, chromium atoms within the grain boundary dif-vulnerable to corrosion. To ensure continued corro- fuse to replace the chromium atoms removed at the sion resistance, processes that breach the protective

!ayer must be avoided. grain boundaries by the precipitated chromium car-bides. This causes a depletion of chromium atoms within the grain boundary, below the minimum level A recent incident involving corrosion of one vendors of 12 percent required for corrosion protection, mak-316L stainless steel irradiator sources was brought to ing the steel susceptible to intergranular corrosion. In NRCs attention. He sources were similar in design this condition, 316L stainless steel is said to be and construction to other manufacturers stainless sensitized.

steel irradiator sources and showed signs of inter-granular corrosion. However, sources from other manufacturers, located in the same irradiator pool, Electrochemical Corrosion-Intergranular I did not show signs of corrosion. An extensive investi-Electrochemical corrosion occurs when you have gation revealed that these corroded sources had been electrically coupled, dissimilar metals or areas within sensitized, thereby making them vulnerable to inter-the same metal immersed in a conducting media granular corrosion.The sensitization occurred during (elcetrolytc). In this circuit, an oxidation reaction oc-shipment of these sources. Temperatures in the ship-ping container exceeded the critical sensitization curs at the anode where the metal ions are ionized and released to the c!cctrolyte. The resulting elec-temperature for 316L stainless steel (see Sensitiza-tion and Electrochemical Corrosion-Intergranular, trons flow from the anode to the cathode (surround-ing area), causing corrosion of the anode.

below). Intergranular corrosion was determined to have occurred as a result of the sensitized sources be- When one area of the material always act as an anode ing in the presence of an electrolyte (conducting lig- and adjoining areas always act as cathodes, the result-uid medium). ing circuit is known as a galvanic cell. Galvanic cells 7

may form as a result of two metals joined or alloyed i ne rate of corrosion that is expected in this situation together, different phases within the same metal, or is hard to predict and is based on a complex relation- precipitation of a second phase at the grain bound- c ship involving time, temperature, and environment. aries of the metc.1 or alloy.ne electrochemicalcorro-Therefore, sources subjected to these conditions and sion occu rring as a result of this type of cell is referred exhibiting signs of corrosion should be immediately to as intergranular corrosion.

isolated and their environment regulated so as to pre-vent further corrosion.

316L stainless steel is vulnerable to in tergranular cor-rosion when the material is sensitized. Intergranular Whenever the safety use of a product relies on its in-corrosion occurs in sensitized 316L stainless steel be-tegrity, and this integrity could be compromised by cause of the precipitated chromium carbides at the corrosion, reviewers should question vendors of grain boundaries. %e grain boundaries become more scaled sources and devices during the safety evalua. anodic compared to the rest of the grain, which acts as 4

the cathode. When in the presence of an electrolyte, corrosion occurs at the grain boundaries.

ONGOING PROJECTS For more information on this matter, please contact NRC-AGREEMENT STATE WORKING GROUP Mr. Thomas Rich at (301) 415-7893.

In J uly 1995, NRC, with the assistance of the Organi-

References:

zation of Agreement States, formed a joint NRC-Agreement State Working Group (WG), to evaluate control and accountability of licensed devices. He Askeland, Donald R., The Science and Engineering of Materials, pp. 672-691, 697-698, Boston: PWS task of the WG was to assess the current regulatory programs for general and specific licensed devices l Publishers,1984.

and determine the baselinc for regulating these devices.

Smith, William E, Structure and Properties of Engi-neering Alloys, pp. 294-305, New York: McGraw- On July 2,1996, the WG submitted its final report to Hill,1981. NRC management. The report included the WGs recommendations to: 1) increase regulatory over-sight of users of certain devices; 2) impose penalties  ;

on persons losing devices; 3) ensure proper disposal l POSSIBLE CONTAMINATION IN of orphaned devices (devices in the public domain KR-85 HANDLING SYSTEMS that are discovered by someone other than the right-ful owner or responsible person-usually a non-licensee); 4) encourage States to implement similar ThJ current process for cleaning hand!5g systems for Kr-85 is to flush and vent them until the readings programs for users of Naturally-Occurring or Accelerator-Produced Material; and, 5) encourage from the exhausted air are below release limits. The

non-licensed stakeholders to take appropriate ac-readings on the outside of the components of the sys-tions, such as instituting programs for material identi-tem are also checked to make sure that they are below acceptable limits. fication.The report will be forwarded to the Commis.

sion for its consideration.

Darin; cleaning and decontamination of some of It should be noted that the WGs recommendr.: ions tm. systems,it has been reported that a varnish-like called for increased oversight of devices containing at residue has been found on the inside of some of the least; 370 MBq (10 mci) of ceshm-137; 3.7 MBq (0.1 system components (e.g., storage nks and compres- rnCi) of strontium-90; 37 MBq (1 mci) of cobalt-60; or sors). The residue is suspected h be a result of oils 37 MBq (1 mci) of any transuranic. However, the rec-and dust in the system accumulating on the inside of ommendations did not suggest restricting use of de-the components through repeated vacuum cycles. vices to specific licensees only. The increased over-This residue is not removed by the flushing process sight could also be incorporated as part of a general currently used to clean the systems. It has been re- licensing program.

ported that several commonly used solvents have been used to try to remove the residue, but that it was he WG only recommeWed design changes m. thela-not easily removed.The residue has been successfully beting of devices. The WG recommended that the la-removed by scraping the internal surfaces of the com- beting of the devices identified above for increased ponents. Residues containing up to 29.6 GBq (800 versight include the device model number and serial mci) of Kr-85 have been reported. Because of the number, the isotope and activity of the radioactive low. level emissions from Kr-85, the presence of the material, the trefoil symbol, the words Caution-Ra-residue is not detectable by measurements from the dioactive Material, and the name of the device ven-outside of the components. dor. The WG also recommended that t he labeling be required to be durable, capable of withstanding likely conditions associated with handling, mage, and use There is a concern that systems released as cleaned of ti.e device, and must be visibic to t.:.s rs of the de-may still contain the residue and be released into the vices. These recommendations would be applicable to scrap stream ior recycle. Of particular concern is that general and specific licensed devices.

parts could be cut tm. noosing the Kr-85 residue, or that the storage tai. ay be reused as a pressuriza- The WG also recommended that the increased over-tion chamber or another storage tank. sight should be a Division-2 item of compatibility for 5

Agreement States.This is consistent with the current For more information on this matter, please contact  ;

regulations for general licensed devices. This allows Mr. John Lubinski at (301) 415-7868.  !

for Agreement States to be more stringent, including t i restricting use of certain devices to a specific license.

THE SSD BULLETIN BOARD SYSTEM I i

Currently, some Agreement States have imple. New information and updates continue to be added to 1

( mented regulations that restrict use of certain de- the SSD BBS on FedWorld. For information on using j vices, that meet the requirements of 10 CFR 32.51, to the FedWorld Systems and general commands, i specific licenses, and some have implemented more please contact the FedWorld help desk at (703) stringent regulations for general licensed devices.  !

487-4608. For assistance in accessing the NRC BBS This means that some Agreement States do not rec- on FedWorld, please contact Arthur Davis at (301) ognize the conditions and approvals in some registra- 415-5780. For questions regarding content of the SSD tion certificates that allow for use of the device under BBS, please contact Michele Burgess at (301) a generallicense. 4155868 or Steve Baggett at (301) 415-7273.

If readers of this newsletter need answers to specific questions, or have information that they believe will be j valuable to other user: nd regulators of sealed sources and devices, we encourage them to provide this information to the SSSS. We will review the submitted information; if we find it to be within the scope of this l newsletter, the information will be covered in a future issue. Send all questions, comments, requests for back 1 issues, or articles to Kim Randall or Doug Broaddus of the SSSS at: SS&D Newsletter, US Nuclear Regulatory Commission, Mail Stop T-8 FS, Washington, DC 20555-0001, or FAX (301) 4155369.  !

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