Radioactive Materials at SSRL

Contact Information

SSRL Safety Officer (650) 926-3861
SSRL Radiation Protection Group (650) 926-4299

Throughout the course of an SSRL Experimental Run, there are requests from users to transport and use small amounts of radioactive material in their experiments, either as stand alone samples or in a matrix of other materials. There is no minimum quantity for declaring the use of radioactive samples at SSRL. The purpose of this procedure is to enable Users, SSRL and SLAC staff to know what radiological controls will be implemented for these materials, based on the isotope, its toxicity risk and radiological controls. Radioactive materials at SSRL are classified into 4 classification Groups based on the radiotoxicity tables, see below.

No Letters of Intent (LOI's) or rapid access applications will be accepted for experiments involving radioactive materials. Experiments that wish to use radioactive materials must go through the normal SSRL proposal process.

Radiological Controls for the conduct of experiments is contained in a SLAC/SSRL document, SSRL Radioactive Material Experiments Radiological Work Controls SLAC - I - 82B - 00100 - 001, and shall be reviewed by all users.


  • Shall submit notice of intent to use Radioactive Materials online in a timely manner, describing the isotope and activity in the required matrix formatting
  • Shall follow all the applicable radiological procedures and postings while running their experiments
  • Report to RPFO and SSRL Safety Staff any unintentional deviations from governing procedure
  • Ensures the shipping papers sent with their materials mirror their declarations and accurately reflect the amount of material shipped in both activity and weight amount

Containment of samples

All sample containment/holder designs shall be approved by the Radioactive Material Experiment Program Manager and SSRL Safety Officer. Many containment designs have been previously approved and do not need re-approval. SSRL and Radiation Protection Department reserves the right to review containment/holders previously approved if devices have not been used within the last two years, to ensure that all radiological requirements at SLAC are met. New sample holder designs/changes not shown/approved in the SSRL Radioactive Sample Holders Catalog must be submitted to SSRL's Safety Officer at , for review and approval prior to shipment to SSRL. Allow at least 60 days for approval. Application for holder is located here: Holder Template

Layers of containment: See end of page Radiotoxicity Table 1 for isotope group classifications

  • Very high radiotoxicity (Group 1) and high radiotoxicity (Group 2) are required to have three (3) levels of containment.
  • Moderate radiotoxicity (Group 3) is required to have two (2) levels of containment.
  • Low radiotoxicity (Group 4) is required to have one (1) level of containment.

In the case of a mixture of radionuclides belonging to different radiotoxicity groups, the highest hazard group will be assigned to the mixture of radionuclides.

Any divergence from this protocol requires further review and approval. For questions or assistance with this procedure, call: SSRL Safety Office (650) 926-3861 or SLAC Radiation Protection Field Operations (RPFO) (650) 926-4299

Note: Sample containment is the SLAC/SSRL Approved physical barrier(s) required to be in place that prevent the release of material.

Procedure for Submitting Radioactive Material information to SSRL

At a minimum, thirty days before the start of the experiment the SSRL Safety Office must be advised of the maximum quantity of radioactive material to be sent, the isotopic composition, and the type of containment design to be utilized. For radioactive materials already on site and inventoried in the RP database, users must submit a 7- day notice.

Users are advised that the maximum quantities listed on the 30-day notice is binding. This gives SLAC a total upper limit of material onsite and allows time to define and configure its radioactive material storage areas, such that SLAC remains in compliance with standards for a Hazard Category below category III per DOE-STD-1027-2018 latest revision.

The users must also be reminded of their responsibility for ensuring the shipping papers sent with their materials mirror their declarations and accurately reflect the amount of material shipped in both activity and weight amount.

Shipments of radioactive materials will not be accepted at SLAC if the shipping papers do not contain the required information. Non-regulated and UN-2910 materials are not required to include in the package container formal shipping papers per IATA/DOT regulations. The 7 and 1day notices will reflect the quantity of radioactive material being sent and the isotopic composition.

NOTE: Do not ship or bring radioactive samples (any amount) to SSRL without receiving written authorization from our Radiation Protection Department. ** International shipments may require additional approvals. Contact SSRL Safety Office or Radiation Protection for additional information.

Shipment and Receipt of Radioactive Material at SSRL

All shipments to SLAC shall have pre-approval from Program Manager or designee and must contain a return authorization number or statement from the Shipper authorizing SLAC to ship the material back. No shipments will be accepted without a proper return authorization. All material will be returned to the origin institution upon termination of the experiments unless the sample material belongs to SSRL.

All hazardous materials, including radioactive materials, shipped to or from SSRL shall be packaged and handled according to U.S. Department of Transport regulations (via highway) or IATA/ICAO Dangerous Goods Regulations (via aircraft or from overseas). Shipments that fail to comply with these federally mandated regulations will be returned to the Users home institution unopened. All radioactive material packages, regardless of carrier,  REGULATED and UNREGULATED, must have a packing slip, affixed to the outside of the package, detailing the radioactive material isotopes amounts and holders in the container and shall be addressed to:

User Name and User Proposal #
SLAC National Accelerator Laboratory
Shipping and Receiving, Bldg. 81
Radiation Protection
Hold for pick by RP
2575 Sand Hill Road
Menlo Park, CA 94025. USA
Tel.: (650) 926-4299

Mark package with user name and proposal number. User must obtain prior authorization from Radiation Protection to ship unregulated materials through USPS. All shipments of radioactive material, including non-regulated per DOT or IATA, must match the authorization request quantities and characteristics. Also the IATA/ICAO and DOT calculations must be based on the same distributions as declared in the 30-day notice in order to be in compliance.

When sending specification packages (Type A, Type B), the documentation of the package certification must be provided prior to offering the shipment. When received, packages will be checked for damage and surveyed for external radiation and contamination. The radioactive material will be inventoried and then released to its custodian/user for experiments at SSRL. All radioactive material leaving SSRL shall be sent back to the User's home institution by RPFO and the material will be removed from the SSRL Radioactive Material Inventory.

In order to ensure compliance with DOE-STD-1027-2018-Change Notice 1, September 1997 tracking, requests for shipment authorization for all radioactive materials shall include the isotopic distribution when applicable. SSRL is strictly limited to the quantities of radioactive material allowed at its facility at any one time. Users must inform the SSRL Safety Office and Radioactive Material Experiment Program Manager of the exact isotopes and quantity of each isotope to be shipped. If shipments arrive at SLAC and the quantity of radioactive material originally specified has been exceeded, samples will be returned to the Users home institution unopened.

Any nano-scale forms of non-radioactive material must be shipped in a packing group (PG I) performance tested package even if the DOT or IATA/ICAO limits are not exceeded.

Materials should be delivered to SLAC in their final containment configuration unless otherwise authorized. Material containment is the SLAC/SSRL approved physical barrier(s) required to be in place to prevent the release of material.

At a minimum, 7 days before the start of the experiment, a request for shipping approval authorization must be sent to the SSRL Safety Office by use of this form (7 day notice authorization). The quantity of radioactive material to be sent, and its isotopic composition, must be specified.

When the samples are shipped to SSRL, the sample shipping information (1-day notice) should be submitted to the SSRL Safety Office through the web application.

All samples shall be surveyed at your home institution prior to shipment to SLAC, and shall be free of removable contamination.

Also provide with the shipping papers the radioactive material license and radiation safety contact at originating lab for the return of radioactive material.

Appropriate forms can be found at the following web address:

The proper shipping address is as follows:
User Name and User Proposal #
SLAC National Accelerator Laboratory
Shipping and Receiving, Bldg. 81
Radiation Protection
Hold for pick by RP
2575 Sand Hill Road
Menlo Park, CA 94025. USA
Tel.: (650) 926-4299

2. Training

In accordance with 10CFR835, SLAC-Radiological Control Manual and SLAC/SSRL procedures, all individuals working with or around radioactive materials are required to complete a level of training commensurate with the hazards in the area.

The minimum training requirements for personnel handling radioactive material is Radiation Worker Training I (RWT I). General Employee Radiation Worker Training (GERT) trained personnel may be utilized as a Continuous Air Monitoring (CAM) watch or for observing work operations. GERT and RWT I training may be completed at SSRL.

3. Transfer of Radiological Training to SSRL

Training from other US Department of Energy laboratories may be transferred to SLAC with RP approval. Personnel who want to transfer their training qualifications will be required to:

  1. Show proof of previous equivalent training such as certificate and date of training. Users must have documentation of training record with completion date available upon requesting the transfer. Training must have been completed within 2 years. The SSRL User Office may also be able to contact your parent laboratory. However this may delay Users ability to acquire dosimetry. At the completion of this training, Users will be issued a SLAC/SSRL identification badge and dosimeter if applicable.

4. Procedures

All experiments within Radiotoxicity Groups 1, 2, or 3 with radioactive material must have a written procedure identifying the radiological hazards and the mitigation controls or a Radiological Work Permit (RWP). Sample of procedures are available upon request. The document must be approved by the SSRL Safety Officer and the Radioactive Material Experiment Program Manager. A document number will be assigned to a procedure by the SSRL Safety Officer. At the conclusion of the experiment, observations noted during the experiment should get incorporated into the procedure(s) as applicable. Experiments within Radiotoxicity Group 4 will have a one page procedure developed and posted by RPFO at the hutch door.

5. Sample Preparation

Material should come already prepared. It is anticipated that some Users will request the ability to perform limited sample preparation of radioactive materials during their stay at SSRL. All proposals of this nature are reviewed on a case by case basis and a request should be submitted to the SSRL Safety Officer 30 days in advance. If sample preparation is allowed then the following provisions shall be employed to manage materials and the risks associated with such activities:

  • Protective clothing shall be worn when working with radioactive materials as directed by Health Physics personnel. All sample preparation shall be performed in a glove bag or other enclosed system such as a hood. The bottom of the hood should be covered with an absorbent paper or equivalent in case of a spill or leak. The hood/containment set up shall vent through a HEPA filter, if used.
  • All radioactive material containments shall be surveyed to detect if removable contamination is present, both entering and leaving the glove bag or hood.
  • Health Physics personnel will provide radiological posting for the area with the appropriate caution or warning "Radioactive Material" signs and a contact telephone number. Contamination surveys of the preparation area will be performed daily when in use by Health Physics personnel, to detect if removable contamination is present.
  • All radioactive material, including any contaminated solids (i.e. glove bag, sample holders, wipes etc.) shall be returned to the Users home institution.
  • A survey meter for radiological monitoring will be made available to the User, along with the requisite instructions for its use and operation. It should be used each and every time radioactive materials are handled in the containment set up, to self-monitor.

6. Radioactive Materials at SSRL Beam Lines

SSRL has approved the following beam lines for Radioactive Experiment: 2-1, 2-2*,2-3*, 4-1*, 4-3,* 6-2b*, 7-2*, 8-2, 10-1, and 10-2, 11-2*. The latest list containing all beam lines approved for radioactive experiments is posted at SSRL website.

Transuranics elements can only run on the beam lines with *.

Any proposal considering a beam line that is not approved for radioactive experiments or transuranic radionuclides, must submit at least a 90 day notice to SSRL Safety Office. The User shall submit a proposal addressing the radiological hazards present in the experiment, and what controls will be in place to mitigate the hazards.

After materials have been surveyed and inventoried by Health Physics personnel, they will be transferred to the User at SSRL. While at the beam lines, radioactive materials need to be controlled in the following manner:

  1. All radioactive materials are to be labeled as such applied by Health Physics personnel.
  2. Radioactive Material not in use shall be stored in either in the beam hutch or designated storage facility.
  3. Beamlines will be posted with appropriate radiological signs by Health Physics personnel.
  4. Transuranic (TRU) materials shall not be left unattended while located within a hutch or vacuum chamber. (EOD - Experimenter on Duty)
  5. All other radioactive materials shall be locked in the hutch/vacuum chamber and the search key returned to the box, should the user need to leave the beam line.
  6. Pre- and post-experiment contamination surveys of the work area will be performed by Health Physics personnel.
  7. Radioactive samples shall not be removed from beam hutches without a survey conducted by Health Physics personnel

7. Chain of Custody

The Chain of Custody transfers the custody of radioactive material between Health Physics personnel and User. Upon opening radioactive material package(s) at SSRL, an electronic chain of custody tag shall be completed by RP to follow the sample during the entire time that the sample is at SSRL. When moving radioactive materials between beam line/hutch and the preparation rooms 113-114, or vice versa, an electronic chain of custody tag shall be completed by RP and requires the user to sign electronically for receipt or disposition of material. The chain of custody should reflect the movement of the sample within SSRL. The electronic chain of custody tag is part of the radiological record to be kept by RPFO.

8. Radiological Controls

Air Monitoring:
Some radioactive materials (Groups 1, 2 alpha emitters) require continuous air monitoring (CAM) while others will require periodic monitoring through a retrospective air sampling. Users may be required to monitor CAM's operations.

At SSRL, a Continuous Air Monitoring (CAM) system is used to provide personnel with an early warning of a spill or release when applicable. Emergency response procedures for use when using CAM's for experiments will be posted at the beam line.

Radiological Coverage:
RP provides Health Physics Technicians (HPT's). An HPT shall be present anytime radioactive materials are moved from/to preparation rooms and beamline/hutches or between beamline/hutches. HPT shall take contamination surveys prior to the physical movement of radioactive materials outside of a beamline/hutch. Health Physics personnel from other DOE laboratories may also provide radiological coverage upon agreement with the SLAC Radiation Protection Department. HPT coverage outside of regular business hours M-F 7am-5pm should be approved by SSRL Safety Office prior to arrival on site.

Emergency Procedures:
Emergencies associated with these experiments can be divided into two categories: those in which there is a possible or known failure of the sample containment resulting in a local emergency specific to these experiments, and those in which some other event, e.g., fire or earthquake, results in a site-wide emergency and a general site-wide response that may need to be modified because of the potential for contamination. In this latter situation, the experimenters will follow the standard facility procedures (as if there were no radioactive materials involved), with the exception that, in the case of transuranics, if it entails no additional risk or hazard to the experimenters, they should take some minimal actions to decrease the possibility of contamination from the experiment. Template procedures with emergency instructions can be obtained from RP.


Very High Radiotoxicity (Group 1)

210 Pb 228 Ra 229 Th 232 U 236 Pu 241 Pu 243 Am 244 Cm 248 Cm 251 Cf
210 Po 227 Ac 230 Th 233 U 238 Pu 242 Pu 240 Cm 245 Cm 248 Cf 252 Cf
223 Ra 227 Th 231 Pa 234 U 239 Pu 241 Am 242 Cm 246 Cm 249 Cf 254 Cf
225 Ra 228 Th 230 U 237 Np 240 Pu 242mAm 243 Cm 247 Cm 250 Cf 254 Es
226 Ra                 255Es

High Radiotoxicity (Group 2)

22 Na 90 Sr 110m Ag 124 I 140 Ba 170 Tm 212 Pb 228 Ac 242 Am 253 Es
36 Cl 91 Y 115m Cd 125 I 144 Ce 181 Hf 207 Bi 232 Th 241 Cm 254m Es
45 Ca 93 Zr 114m In 126 I 152 Eu(13a) 182 Ta 210 Bi 230 Pa 249 Bk 255 Fm
46 Sc 94 Nb 124 Sb 131 I 154 Eu 192 Ir 211 At 236 U 246 Cf 256 Fm
60 Co 106 Ru 125 Sb 134 Cs 160 Tb 204 Tl 224 Ra 244 Pu 253 Cf Th Nat

Moderate Radiotoxicity (Group 3)

7 Be 52 Fe 82 Br 97 Zr 105 Ag 134 Te 143 Ce 171 Tm 198 Au 237 U
14 C 55 Fe 74 Kr 90 Nb 111 Ag 120 I 142 Pr 175 Yb 199 Au 240 U
18 F 59 Fe 77 Kr 93m Nb 109 Cd 123 I 143 Pr 177 Lu 197 Hg 240U+
24 Na 55 Co 87 Kr 95 Nb 115 Cd 130 I 147 Nd 181 W 197m Hg 240 Np
31 Si 56 Co 88 Kr 95m Nb 115m In 132 I 149 Nd 185 W 203 Hg 239 Np
32 P 57 Co 86 Rb 96 Nb 113 Sn 132m I 147 Pm 187 W 200 Tl 234 Pu
33 P 58 Co 83 Sr 90 Mo 125 Sn 133 I 149 Pm 183 Re 201 Tl 237 Pu
35 S 63 Ni 85 Sr 93 Mo 122 Sb 135 I 151 Sm 186 Re 202 Tl 245 Pu
38 Cl 65 Ni 89 Sr 99 Mo 121 Te 135 Xe 153 Sm 188 Re 203 Pb 238 Am
41 Ar 64 Cu 91 Sr 96 Tc 121m Te 132 Cs 152m Eu (9h) 185 Os 206 Bi 240 Am
42 K 65 Zn 92 Sr 97m Tc 123m Te 136 Cs 155 Eu 191 Os 212 Bi 244mAm
43 K 69m Zn 90 Y 97 Tc 125m Te 137 Cs 153 Gd 193 Os 220 Rn 244 Am
47 Ca 72 Ga 92 Y 99 Tc 127m Te 131 Ba 159 Gd 190 Ir 222 Rn 238 Cm
47 Sc 73 As 93 Y 97 Ru 129m Te 140 La 165 Dy 194 Ir 226 Th 250 Bk
48 Sc 74 As 86 Zr 103 Ru 131 Te 134 Ce 166 Dy 191 Pt 231 Th 244 Cf
48 V 76 As 88 Zr 105 Ru 131m Te 135 Ce 166 Ho 193 Pt 234 Th 254 Fm
51 Cr 77 As 89 Zr 105 Rh 132 Te 137m Ce 169 Er 197 Pt 233 Pa  
52 Mn 75 Se 95 Zr 103 Pd 133m Te 139 Ce 171 Er 196 Au 231 U  
54 Mn     109 Pd   141 Ce        

Low Radiotoxicity (Group 4)

3 H 60m Co 81 Kr 91m Y 96m Tc 133 Te 125 Cs 138 Cs 207 Po 243 Pu
15 O 61 Co 83m Kr 88 Nb 99m Tc 120m I 127 Cs 137 Ce 227 Ra 237 Am
37 Ar 62m Co 85m Kr 89 (66m)Nb 103m Rh 121 I 129 Cs 191m Os 235 U 239 Am
51 Mn 59 Ni 85 Kr 89 (122m)Nb 113m In 128 I 130 Cs 193m Pt 238 U 245 Am
52m Mn 69 Zn 80 Sr 97 Nb 116 Te 129 I 131 Cs 197m Pt 239 U 246mAm
53 Mn 71 Ge 81 Sr 98 Nb 123 Te 134 I 134m Cs 203 Po U nat 246 Am
56 Mn 76 Kr 85m Sr 93m Mo 127 Te 131m Xe 135 Cs 205 Po 235 Pu 249 Cm
58m Co 79 Kr 87m Sr 101 Mo 129 Te 133 Xe 135m Cs      
  1. Radionuclides not included in Table I shall, where necessary, be assigned to a toxicity group by the Radioactive Material Experiment Program Manager or his/her designee.
  2. In the case of a mixture of radionuclides belonging to different radiotoxicity groups, the highest hazard group will be assigned to the mixture of radionuclides.
  3. Radiotoxicity Table I is used to determine the number of layers needed in a containment to encapsule the sample and the type of air sample to be conducted; real time or retrospective air sampling.
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