IRRI RADIATION SAFETY MANUAL RL-RSM00-R01

Transcription

1 Issue Date: Revision No.: 01 Page: 1 of 59 Grain Quality and Nutrition Center oratory IRRI RADIATION SAFETY RL-RSM00-R01 This document is issued under the authority of MS. LILIA R. MOLINA IRRI Radiation Safety Officer THIS IS A CONTROLLED DOCUMENT Copy No. 01 Revision No. 01 Issued To Issue Date

2 Issue Date: Revision No.: 01 Page: 2 of 61 REVISION RECORD Revision Description of Change Author Effective Date 0 Initial release R.Jimenez 2004-Oct. 1 Revision and updating LMolina 2011-Jan.23

3 Issue Date: Revision No.: 01 Page: 3 of 61 TABLE OF CONTENTS REVISION RECORD... 2 TABLE OF CONTENTS... 3 PREFACE INTRODUCTION RADIATION SAFETY ORGANIZATIONAL STRUCTURE Radiation Safety Officer Assistant RSO Principal Investigator Workers (Authorized Staff) POLICIES AND REGULATIONS ON RADIATION USE ALARA Program Philippine Nuclear Research Institute Standards for Protection Against Radiation Procedure for Obtaining Authorization to Use Radiation Sources PNRI Inspection of Radiation Sources and Facilities Sanctions for Non-compliance TRAINING PROGRAM Topics included in the Radiation Safety Course Radioactivity and Radiation Units Biological Effects of Radiation External and Internal Radiation Exposures Nature and Properties of Some Radioisotopes Used in Agriculture Exposure Limits for Workers and the General Public RADIOISOTOPE LABORATORY MANAGEMENT Radiation Facilities General Lab Safety Rules Area Restrictions Radiation Survey Monitoring Procedure Decontamination Procedure Decommissioning RADIOACTIVE MATERIALS (RAM) MANAGEMENT Guidelines for Ordering and Receiving Radioactive chemicals/instruments with sealed sources Labeling Requirements RAM Storage Procedure... 44

4 Issue Date: Revision No.: 01 Page: 4 of Transport of Radioactive Materials Inventory and Security Transfer PERSONNEL MONITORING PROGRAM Schedule Reliability Records Minor Spills Involving No Radiation Hazard to Personnel Major Spills Involving Radiation hazard to Personnel Accidents Involving Radioactive Dusts, Mists, Fumes, Organic Vapors and Gases Injuries to Personnel Involving Radiation Hazard Fires or Other Major Emergencies RADIOACTIVE WASTE MANAGEMENT Segregation Labeling and Record Keeping Requirements Quantifying Levels of Radioactivity in Waste Interim Storage of Radioactive Wastes Methods of Disposal APPENDICES Appendix 1 - Definition of Terms Appendix 2. Details on CPR Part Appendix 3. Required forms for obtaining Authorization to Use Radiation Sources Appendix 4. - Code of PNRI Regulations (CPR Part 4) REFERENCES IMPORTANT CONTACT NUMBERS... 61

5 Issue Date: Revision No.: 01 Page: 5 of 61 PREFACE The strives to provide a safe and healthful environment for all persons, including the research and administrative staff, students, and visitors, involved with the handling of hazardous materials. Attainment of this goal requires the cooperation and commitment of all persons involved. While the IRRI Safety and Security Office plans and recommends policies in all matters pertaining to safety and health in the workplace, organizational unit heads, managers, and supervisors are directly responsible for maintaining an atmosphere that promotes full compliance with safety policies and procedures. With regard to radiation safety matters, the Radiation Safety Officer (RSO), nominated by the Deputy Director General for Research, is responsible for the effective implementation of radiation policies and procedures established in accordance with requirements set forth by the Philippine Nuclear Research Institute (PNRI). The PNRI is the agency mandated by the Philippine government to institute regulations on the peaceful uses of radiation sources and to carry out enforcement of said regulations to protect the health and safety of radiation workers and the general public. This manual presents the essential elements of the IRRI s Radiation Safety Program. It consists of the policies, and procedures and relevant information intended to assist all users of radioactive materials in meeting their safety responsibilities while utilizing the unique advantages of radiation sources. The program supports the objective of maintaining all exposures at levels "As Low As Reasonably Achievable" (ALARA). It is essential that all members of the IRRI community become and remain thoroughly familiar with their responsibilities for compliance with health and safety regulations, including the radiation safety policies and procedures contained in this manual. Everyone involved with the use of radioactive material in any way is required to be familiar with the provisions of this manual. IMPORTANT CONTACT NUMBERS: Lily Molina (RSO) loc and 2435 (office) Tel # : (residence) Ruffy Manuel loc Safety Office loc. 2222

6 Issue Date: Revision No.: 01 Page: 6 of 61 RL-RSM00-R01 RADIATION SAFETY 1. INTRODUCTION The is authorized by the Philippine Nuclear Research Institute (PNRI), to acquire, receive, possess, own, and use radioactive materials, as described in Radioactive Material License No. R , for the purpose and place specified and subject to the general and specific conditions stipulated therein. In planning an experiment involving the use of radioisotopes, the Principal investigator must first submit the proposal to IRRI s Radiation Safety Officer (RSO) for review and approval. Although the RSO allows flexibility in dealing with the research uses of radioisotopes on campus, the responsibility rests on organizational unit heads and principal investigators to utilize radioactive materials safely and to comply with state regulations. This manual is a compilation of the regulations applicable to utilization of radioactive material at IRRI. A copy must be available in each Authorized Staff's facility where radioactive materials are used. As a general principle of radiation safety and as a policy of the institute, exposure to radiation should be maintained at levels that are as low as reasonably achievable (ALARA). The use of radioactive materials is a privilege, not a right. Everyone concerned is expected to maintain a safe and compliant workplace. 2. RADIATION SAFETY ORGANIZATIONAL STRUCTURE 2.1. Radiation Safety Officer A qualified Radiation Safety Officer (RSO), designated by IRRI management, shall be responsible for implementing the radiation safety program. Through the RSO, IRRI shall ensure that radiation safety activities are being performed in accordance with regulatory requirements and approved procedures Qualifications and requirements of RSO: a) The RSO shall have completed one hundred twenty (120) hours of formal training and instructions on radiation physics, radiation safety, nuclear regulations and

7 Issue Date: Revision No.: 01 Page: 7 of 61 safe transport of radioactive materials, or an equivalent course as may be determined by PNRI. b) Official Designation/Appointment by IRRI Management. A copy of the document that designates/appoints the individual who will be the RSO, together with a resume of his/her relevant training and experience, must be submitted to PNRI. The document should bear the signature of a representative of management, usually the IRRI Deputy Director General for Research. c) Proof of Consent/Acceptance by RSO. The submitted documents must show proof that the designated RSO has accepted and consented to his designation in writing. d) Statement of Authority and Responsibilities. IRRI management shall provide the RSO sufficient authority, organizational freedom, and management prerogative to: Identify radiation safety problems Initiate, recommend, or provide corrective actions, and Verify implementation of corrective actions Duties and Responsibilities a) Ensure that licensed material possessed by IRRI is limited to the kinds, quantities and forms listed on the license. b) Ensure that individuals using the material are properly trained and are informed of all changes in regulatory requirements and deficiencies identified during annual management audits or PNRI inspections. c) Ensure that personnel monitoring devices are used as required and that reports of personnel exposure are reviewed in a timely manner. d) Ensure that material is properly secured against unauthorized removal at all times when material is not in use. e) Ensure that proper authorities are notified in case of accident, damage, fire or theft, in accordance with the most recently approved emergency plan. f) Ensure that audits are performed at least annually to determine that: IRRI complies with PNRI regulations and the terms and conditions of the license. The radiation protection program content and implementation achieve occupational doses and doses to members of the public that are ALARA; and Records with all required information (e.g. personnel exposure, receipt, transfer, and disposal of licensed material, user training) are sufficient to comply with PNRI requirements. g) Ensure that the results of the audits, identification of deficiencies, and recommendations for change are documented, provided to management for

8 Issue Date: Revision No.: 01 Page: 8 of 61 review, and maintained for at least 5 years. Ensure prompt action is taken to correct deficiencies. h) Ensure that all incidents, accidents, and personnel exposure to radiation more than ALARA levels are investigated and reported to PNRI within the required time limits. i) Ensure that licensed material is transported in accordance with all applicable PNRI requirements. j) Ensure that spent licensed material and wastes contaminated with radioactive material are disposed of properly Assistant RSO Upon the recommendation of the RSO, the representative of IRRI management may also designate an Assistant RSO who shall act for on behalf of the RSO in his/her absence Requirements: a) The ARSO shall have completed at least one hundred twenty (120) hours of formal training on radiation physics, radiation safety, nuclear regulations and safe transport of radioactive materials OR forty (40) hours of formal training plus relevant experience as an Authorized Staff in handling major radioisotopes currently used at IRRI. b) Official Designation/Appointment by IRRI Management. A copy of the document that designates/appoints the individual who will be the ARSO, together with a resume of his/her relevant training and experience, must be submitted to PNRI. The document should bear the signature of a representative of management, usually the IRRI Deputy Director General for Research. c) Proof of Consent/Acceptance by ARSO. The submitted documents must show proof that the designated ARSO has accepted and consented to his designation in writing Duties and Responsibilities: a) Act on behalf of the RSO in his/her absence. b) In-charge of radioisotope facilities and activities in his work area. c) Keep and maintain appropriate records of all radioisotope activities (routine survey monitoring of facility, inventory of radioisotopes, type, volume and activity of wastes generated and disposed of) and provide copies of these records to the RSO.

9 Issue Date: Revision No.: 01 Page: 9 of Principal Investigator The Principal Investigator is directly responsible for compliance with all regulations governing radiation safety in the laboratory, and for safe practices of individuals working under his/her supervision Requirements: Relevant work experience and/or training Duties and Responsibilities: a) Prepare and submit research proposal and justification for the use of radioactive material in his/her research work, as required for inclusion in the PNRI Radioactive Material License for IRRI, and for subsequent annual renewal of the license. b) Outline procedures to be followed in proposed activity, from introduction of radiotracer up to analysis, indicating how the labeled material will be handled and how the activity will be monitored. c) Use radioactive materials according to statements, representations and conditions set forth in the radioactive materials use license. d) Responsible for individuals working under his/her control. Ensure that Authorized Staff (lab technicians, students, visitors, researchers, scientists) in his work area are properly supervised, trained and informed of the institute s Radiation Safety Program to enable safe working habits and prevent exposures to themselves and others and/or contamination of the work areas or environment. Ensure that film badges are worn appropriately by Authorized Staff when working with radioisotopes and are placed in a designated rack after use. Ensure timely submission of film badges and survey meters to the RSO for proper evaluation and calibration at PNRI Ensure proper disposal of radioactive wastes generated from activities in his work area e) Ensure that radiation safety surveys and audits in the laboratory are conducted, and maintain records for review. f) Maintain inventory and record of the various forms (physical and chemical) and quantities of radiation which are present in his work areas. Provide the RSO with

10 Issue Date: Revision No.: 01 Page: 10 of 61 current records of the receipt and the disposition of radioactive material in their possession including use in research, waste disposal, transfer, storage, etc. g) Maintain constant surveillance and immediate control of radioactive materials to prevent unauthorized removal or tampering, and/or assure that all of the workers occupying the area maintain security. Post warnings and restrict entry to areas that contain potentially hazardous radioactivity or chemicals. Label radioactive use equipment and work areas. h) Notify the RSO of any changes in procedure or personnel, or licensed activities/materials in his work area that would require an amendment to the license, including transfer of radioactive materials/facilities, new radioisotope users, and decommissioning of facilities. Changes from the approved procedures must be approved by PNRI in an amendment or new application prior to the implementation of the change. i) Assure designation of a responsible individual to oversee radioisotope work during short absences, and of a stand-in principal investigator during extended absences Workers (Authorized Staff) The term "Authorized Staff" is used to identify an individual who is authorized in the license to use radioactive material in the course of his/her employment or study. Authorized Staff may be a Principal Investigator, Assistant Scientist, Researcher, Graduate student, Technician, Post-doctorate, Visitor, or any other individual who will handle radioactive material. Since they are the direct handlers of the radioactive material, the final responsibility lies with them for safety and compliance with laws and regulations Requirements a) The authorized staff shall have completed a basic radiation safety course that includes forty (40) hours of training on radiation physics, radiation protection, safe handling and transport of radioactive material, or an equivalent course as may be determined by PNRI. b) Official authorization. A list of persons who will use radioactive materials under a certain project should be certified and submitted by the project s Principal Investigator for inclusion in the PNRI Radioactive Material License for IRRI. c) Must fill out NRLSD/LRE-008a form and, together with a Certificate of Training, submit to PNRI, through RSO.

11 Issue Date: Revision No.: 01 Page: 11 of Duties and Responsibilities a) Adhere to all laws, rules, regulations, license conditions and guidelines pertaining to the use of radioactive materials. b) Wear assigned film badge during handling of radioactive materials. (See Personnel Monitoring for details on film badge requirements.) c) Practice ALARA (As Low As Reasonably Achievable) in their work, and minimize the potential for exposures, contamination or release of radioactive materials. d) Clean any contamination or spills that occur in his/her work area. The work area must be monitored by the user after each use. If contamination is found, it must be cleaned up immediately. DO NOT LEAVE IT FOR ANOTHER PERSON TO CLEAN UP. e) Follow strictly experimental procedures. No changes in procedures using radioactive materials are to occur without the approval of the principal investigator. (Do not take short cuts. Changes in experimental procedures impacting upon safety must be approved by the RSO) f) Report immediately any abnormal occurrence to the principal investigator, such as spills, significant contamination, equipment failure, and loss of film badges. g) Return the film badges on time and report any loss or contamination of the film badge to the RSO. h) Inform the RSO of any exposures which have occurred at a previous employer when beginning employment at IRRI. Also, notify the RSO of termination of employment and return the film badge at the end of employment. i) Maintain security of radioactive materials. j) Segregate and properly label radioactive and/or radioactive-contaminated wastes for proper disposal. 3. POLICIES AND REGULATIONS ON RADIATION USE 3.1. ALARA Program IRRI is committed to the program described herein for keeping individual and collective doses As Low As Reasonably Achievable (ALARA). In accord with this commitment, policies and procedures are hereby prescribed to ensure radiation exposures to all persons associated with the organization are minimized: The RSO will review annually radiation worker doses, to determine whether exposures are being kept to a minimum. When levels are exceeded, the worker will be

12 Issue Date: Revision No.: 01 Page: 12 of 61 notified and work practices reviewed, in order to attempt to lower the exposure if possible The RSO will brief management once per year regarding occupational exposure levels The RSO will carefully review applications for radioactive material authorization, to ensure that the applicant is qualified and that the proposal incorporates the ALARA philosophy. Modifications or alternatives to operating procedures will be recommended if they will reduce exposures unless the cost is considered justified The RSO will perform an annual review of the Radiation Safety Program, including ALARA considerations. This will include reviews of operating procedures and past dose records, inspections, etc., and consultations with PNRI or outside consultants Philippine Nuclear Research Institute Republic Act 2067 and Republic Act 5207, both as amended, established and provided the authority for the Philippine Atomic Energy Commission (PAEC), now the Philippine Nuclear Research Institute (PNRI), to promote and at the same time regulate the application and use of radioactive materials in the Philippines Nuclear Regulations, Licensing and Safeguards Division (NRLSD) of PNRI is responsible for the regulatory control of radioactive materials. NRLSD is composed of five (5) sections: a) Standards Development Section develops regulations, regulatory guides, and standards related to atomic energy facilities and radioactive materials. b) Licensing, Review and Evaluation Section reviews license applications and maintains the database of licensees and radioactive materials in its possession. All licenses are issued on an annual basis, for which the licensee has to pay the license fees. Records are kept of each license or licensee. c) Inspection and Enforcement Section conducts regulatory inspection and enforcement activities. The section has developed inspection plans and checklists for particular practices that are used during the inspection. The inspections are conducted on a yearly basis. Follow-up or unannounced inspections are conducted to verify implementation and completion of licensee s commitment on certain inspection findings. d) Safeguards Section maintains the system for accounting and control of nuclear materials. It is responsible for the security of radioactive sources and maintains the database of sealed sources based on information available from the LRE

13 Issue Date: Revision No.: 01 Page: 13 of 61 records. The section also maintains a database of reported missing or stolen sources. e) Radiological Impact Assessment Section responsible for emergency planning and preparedness for radiological accidents or incidents and dose assessments. It also provides regulatory research activities in aid of the regulations Rules and Regulations on the Use of Radiation Sources in the Philippines. PNRI has established the Code of PNRI Regulations containing the rules and regulations for the specific category of use of radioactive materials. The rules are identified as parts of the Code and are properly identified as CPR Part Numbers Standards for Protection Against Radiation Code of PNRI Regulations (CPR) Part 3. Standards for Protection Against Radiation The provisions of this Part prescribe the safety limits, standards, and procedures that must be followed by authorized persons to protect its workers and the public against the hazards of radiation and to protect the radioactive materials from unauthorized use. CPR Part 3 adopts the recommendations of the International Basic Safety Standards for Radiation Protection (IBSS) published by the International Atomic Energy Agency (IAEA).(See Appendix 2. for details on CPR Part 3) 3.4. Procedure for Obtaining Authorization to Use Radiation Sources Approval for the use of radioactive materials is given by PNRI for a period of one year, and is reviewed annually. IRRI, through the RSO, should file the application with PNRI at least 30 working days before the expiration date of the previous license. Normally, the license expires at the end of February and application for renewal should be filed before 15th of January Requirements. To obtain authorization, the Principal Investigator or his designated staff, must submit the following completed forms (see Appendix 3) to the RSO. a) Application for Inclusion in the PNRI Radioactive Material License for IRRI (RIL Form 1) b) List of Radioactive Materials/Labeled Compounds (RIL Form 2a) c) List of Radioactive Materials/Sealed Sources (RIL Form 2b) d) Research Proposal (RIL Form 3) e) List of Proposed Authorized Staff (RIL Form 4)

14 Issue Date: Revision No.: 01 Page: 14 of 61 f) Accomplish one NRLSD/LRE Form No. 008a for each person in the list and enclose a copy of Certificate of Training g) List of Survey Instruments for radiation detection use at the designated work area (RIL Form 5) PNRI may require additional conditions under which the use of the material must be conducted. Upon approval of application, the Principal Investigator may then order, receive, and use the material according to the statements and representations made in the application, and any conditions set forth by PNRI in the license. Violations or noncompliance may be cause for suspension or termination of the authorization to receive and use radioisotopes PNRI Inspection of Radiation Sources and Facilities PNRI conducts regulatory inspection on a yearly basis. Follow-up or unannounced inspections are also conducted to verify implementation and completion of licensee s commitment on certain inspection findings. The RSO should provide pertinent records to the PNRI inspectors upon their request and access to radioisotope laboratory facilities Sanctions for Non-compliance Each radioactive materials user should understand and remember that there is only one license for the entire institute. Any individual or any action that endangers the license compromises the permission of all researchers to utilize radioactive material at IRRI. Hence, the license places significant responsibility on each individual who uses radioactive materials to conform with safe work practices, and to conduct and complete all required duties, however large or small they may be Sanction system. IRRI confers authority upon the RSO to police the ranks of all users and handlers of radioactive materials in the institute and to impose sanctions for noncompliance. A sanction system for violations or instances of noncompliance consists of the following: a) A report is sent to the Principal Investigator, detailing the violation or noncompliance and the corrective action/s required. b) If the problems are corrected, no further actions will be required. If not corrected, a Notice of Noncompliance may be sent to the Principal Investigator requiring a response in writing and further corrective actions.

15 Issue Date: Revision No.: 01 Page: 15 of 61 c) Sanctions will be imposed depending on the severity level of the violation or noncompliance shown in Table 1. Table 1. Levels of violation and corresponding sanctions. Level Violation Sanction/s I II III Serious violation which cause immediate risk or danger to safety, health, release to the environment of substantial quantities, doses to humans. Serious Violation but does not present immediate risk to health, safety, the environment or the license A minor a) Violation noted by RSO and sent to IRRI Safety and Security Office b) Letter to PI from RSO; response is required in writing c) Require PI to immediately submit written corrective actions to RSO d) Require PI to appear before an investigation committee e) Close surveillance by SSO and RSO to ensure corrective measures are enforced f) Require involved personnel to attend refresher course on radiation safety g) Place restrictions on staff causing non-compliance h) Suspend shipments of radioactive materials to PI i) Decrease scope or limits of radioactive materials approval j) Require PI to reapply for radioisotope use k) Confiscate radioactive materials in possession of PI l) Permanently terminate approval to use radioactive materials a) Violation noted by RSO and sent to IRRI Safety and Security Office b) Letter to PI from RSO; response is required in writing c) Require PI to immediately submit written corrective actions to RSO d) Require PI to appear before an investigation committee e) Close surveillance by RSO to ensure corrective measures are done f) Require involved personnel to attend refresher course on radiation safety g) Place restrictions on staff causing non-compliance a) Violation noted by RSO and memo sent to Authorized Staff

16 Issue Date: Revision No.: 01 Page: 16 of 61 violation, typically a technical matter such as failure to properly label materials and wastes with all the required information; record keeping errors of minor impact. Poses no immediate risk to health, safety or environment. A minor noncompliance issue, but when seen repeatedly, may be escalated to a higher level. b) Require Authorized Staff to immediately correct violation c) Close surveillance by RSO to ensure corrective measures are done d) Require involved personnel to attend refresher course on radiation safety IRRI, through the RSO, should within twenty-four (24) hours notify PNRI by telephone or by any other fast means of any incident involving licensed radioactive materials which may have caused or threatens to cause unnecessary risk to the health and safety of the public. A subsequent written report detailing the circumstances and the corresponding actions undertaken shall be submitted within thirty (30) calendar days from the time the report was made. 4. TRAINING PROGRAM Before assuming duties involving use of radioisotopes or handling of equipment with sealed sources, it is mandatory that all workers, including principal investigators attend at least 40 hours training course on handling of radioactive materials at the Philippine Nuclear Research Institute (PNRI). Certification is obtained after successful completion of the course and passing the examination. Radiation workers new to IRRI but with significant training and experience in handling radioactive materials, including new IRS and/or short-term visitors, should submit a copy of certification of training obtained elsewhere and/or of relevant work experience. The RSO may request prior radiation dose histories from past employers.

17 Issue Date: Revision No.: 01 Page: 17 of Topics included in the Radiation Safety Course Basics on Radioactivity and Radioactive Decay Quantities and Units / Interaction of Radiation Radiation Detection Biological Effects of Radiation Basic Principles of Radiation Protection Radiation Control Practices and Handling Techniques Radioactive Waste Management Radiation Monitoring Calculations Basic to the Use and Measurement of Radioactivity Nature and Properties of Radioisotopes Used in Agriculture Laboratory Design Contamination / Decontamination (lecture/demo) Emergency Procedures Safe Transport of Radioactive Materials Licensing Rules and Regulations Characteristics of Geiger-Mueller Detector / Statistics of Counting 4.2. Additional instructions / orientation should be given by the Principal Investigator or his designated Authorize Staff to new users on the following subjects: IRRI s Radiation Safety Program In-house laboratory rules and procedures.

18 Issue Date: Revision No.: 01 Page: 18 of Areas where radioactive materials are used or stored Potential hazards associated with radioactive material in each area where the employees will work Each individual s obligation to report unsafe conditions to the RSO Location where the licensee has posted or made available, notices, copies of pertinent regulations, and copies of pertinent licenses and pertinent conditions Radioactivity and Radiation Units Radioactive material is defined as any material or combination of materials that spontaneously emits ionizing radiation. Ionizing radiation has the ability to remove electrons from atoms, creating ions; hence, the term "ionizing radiation". The result of ionization is the production of negatively charged free electrons and positively charged ionized atoms. There are four types of ionizing radiation involved that can be classified into two groups: 1) photons, such as gamma and x-rays, and 2) particles, such as beta particles (positrons or electrons), alpha particles (similar to helium nuclei, 2 protons and 2 neutrons), and neutrons (particles with zero charge, electrically neutral). Photons are electromagnetic radiation having energy, but no mass or charge; whereas particles have typically both mass and charge as well as energy. Neutrons have mass and energy, but no charge, and are typically produced by man with machines, such as cyclotrons. All types of ionizing radiation can remove electrons, but interact with matter in different ways. Ionized atoms (free radicals), regardless of how they were formed, are much more active chemically than neutral atoms. These chemically active ions can form compounds that interfere with the process of cell division and metabolism. Also, reactive ions can cause a cascade of chemical changes in the tissue. The degree of damage suffered by an individual exposed to ionizing radiation is a function of several factors: type of radiation involved, chemical form of the radiation, intensity of the radiation flux (related to the amount of radiation and distance from the source), energy, and duration of exposure. Radioactive materials have an associated half-life, or decay time characteristic of that isotope. As radiation is emitted, the material becomes less radioactive over time, decaying exponentially. Since it is impossible or impractical to measure how long one atom takes to decay, the amount of time it takes for half of the total amount of radioactive material to decay is used to calculate half-life.

19 Issue Date: Revision No.: 01 Page: 19 of Radioactive decay. The equation which is used to calculate radioactive decay is shown below. A = A 0 e λ t Where: A = Current amount of radioactivity A 0 = Original amount of radioactivity e = base natural log = λ= the decay constant = / t 1/2 (where t 1/2 = half-life) t = the amount of time elapsed from A 0 to A It is important to be careful of the units used for the time. Days, hours and years must not be mixed in the calculation Units of Activity. Quantify the amount of radiation emitted by a given radiation source. Activity can be measured with an appropriate radiation detection instrument. Most of these measurements are made with a liquid scintillation counter, gamma well counter or Geiger-Mueller (GM) survey meter with appropriate detection probes. These instruments detect a percentage of the disintegrations and display in counts per minute (CPM). It is important to note that the CPM readings from survey instruments are not the true amount of radiation present, since there are factors which decrease the detection capability of even the most sensitive instruments. Two factors influence radiation detection sensitivity: the geometry of the counting system and the energy of the radionuclide being measured. Lower energy radionuclides are detected with lower efficiencies than higher energy radionuclides. Detection instruments are calibrated with known sources with different energy levels to determine the efficiency of the instrument in order to account for these variables. To make the necessary conversion to the microcurie unit, the following formula must be used in all records of surveys, waste materials or radioactive solutions generated within the facility. CPM/Efficiency = DPM DPM/2.22 x 106 = uci

20 Issue Date: Revision No.: 01 Page: 20 of 61 Special Units Curie, Ci = 3.7 x DPS disintegrations (particles or photons) per second = 2.22 x DPM Millicurie, mci = Ci Microcurie,uCi = Ci Gigabecquerel, GBq International Units (SI) Becquerel, Bq = 1 DPS (disintegration per second.) Megabecquerel = 10 6 Bq, MBq = 10 9 Bq Units of Exposure (Dose) Quantify the amount of radiation absorbed or deposited in a specific material by a radiation source. Special Units Roentgen, R = quantity of γ or x- radiation to produce ions with charge of 2.58 x 10-4 coulombs per kg air Radiation Absorbed Dose, rad Equivalent Dose, rem Effective Dose, J/kg = 100 ergs of energy deposition per gram of absorber International Units (SI) Coulomb/Kg = x 10 3 R Absorbed Dose, Gray, Gy = 100 rads = rad x ΣW R Equivalent Dose, Sievert, Sv = 100 rem Equivalent Dose, = rem x ΣW T Sievert, Sv = 100 rem W R = radiation weighing factor for the type and energy of radiation incident and is independent of tissue or organ ΣW T = tissue weighing factor for tissue T 4.4. Biological Effects of Radiation Injury due to irradiation is caused mainly by ionization within the tissues of the body. When radiation interacts with a cell, ionizations and excitations are produced in either biological macromolecules or in the medium in which the cellular organelles are suspended, predominantly water. Based on the site of

21 Issue Date: Revision No.: 01 Page: 21 of 61 interaction, the radiation-cellular interactions may be termed as either direct or indirect Direct action occurs when an ionizing particle interacts with and is absorbed by a macromolecule in a cell (DNA, RNA, protein, enzymes, etc.). These macromolecules become abnormal structures which initiate the events that lead to biological changes Indirect action involves the absorption of ionizing radiation in the medium in which the molecules are suspended. The molecule which most commonly mediates this action is water. Through a complex set of reactions the ionized water molecules form free radicals that can cause damage to macromolecules The most important target for radiation in the cell is DNA in the nucleus. Biological effects result when DNA damage is not repaired or is improperly repaired. Extensive damage to DNA can lead to cell death. Large numbers of cells dying can lead to organ failure and death for the individual. Damaged or improperly repaired DNA may develop into lymphoma and cancers in somatic cells Two kinds of effects a) Acute, or nonstochastic, effects are health effects, the severity of which varies with the dose and for which a threshold is believed to exist. Radiationinduced cataract formation is an example of a nonstochastic effect (also known as a deterministic effect). b) Delayed, or stochastic, effects, are health effects that occur randomly and for which the probability of the effect occurring, rather than the severity, is assumed to be a linear function of the dose without threshold. Genetic effects and cancer incidence are examples of stochastic effects Sensitivity. Various degrees of sensitivity to radiation exist due to the type of tissue which receives the exposure, and are shown below: Radiosensitive Breast tissue Bone marrow cells Less Radiosensitive Heart tissue Large arteries

22 Issue Date: Revision No.: 01 Page: 22 of 61 Mucosa lining of small intestines Sebaceous (fat) glands of skin Immune response cells All stem cell populations Lymphocytes Large veins Mature blood cells Neurons Muscle cells 4.5. External and Internal Radiation Exposures External hazards These hazards arise when radiation from a source external to the body penetrates the body and causes a dose of ionizing radiation. These exposures can be from gamma or x-rays, neutrons, or beta particles; they are dependent upon both the type and energy of the radiation. Most beta particles do not normally penetrate beyond the skin, but when sufficiently intense, can cause skin and/or eye damage. Very energetic beta particles, such as those emitted by 32P, can penetrate several millimeters into the skin. Shielding is needed in order to reduce the external radiation exposure. Typically, a maximum of 1/2 inch thick sheet of Plexiglas is an effective shield for most beta particles. Alpha particles, because of higher mass, slower velocity, and greater electrical charge compared to beta particles, are capable of traveling a few inches in air and rarely penetrate the outer dead skin layer of the body. Therefore, alpha particles typically are not an external radiation hazard. X and gamma rays, along with neutron radiation, are very penetrating, and are of primary importance when evaluating external radiation exposure and usually must be shielded. The onset of first observable effects of acute radiation exposure, diminished red blood cell count, may occur at a dose of approximately 100 rads of acute whole body radiation exposure. The LD50 for humans (lethal dose where 50% of the exposed population may die from a one time exposure of the whole body) is about 500 rads, assuming no medical intervention. Exposure to external radiation may be controlled by limiting the working time in the radiation field, working at a distance from the source of radiation, inserting shielding between the worker and the source, and by using no more radioactive material than necessary.

23 Issue Date: Revision No.: 01 Page: 23 of Internal exposures These arise when radiation is emitted from radioactive materials present within the body. Radioactive materials may be internally deposited in the body when an intake occurs through one of the three routes of entry: inhalation, ingestion and skin contact. These exposures can occur when radioactive material is airborne; is inhaled and absorbed by the lungs and deposited in the body; is present in contaminated food, drink or other consumable items and is ingested; or is spilled or aerosolizes onto the skin and absorbed or enters through cuts or scratches. Internal deposition may also result from contaminated hands, with subsequent eating or rubbing of eyes. Although external hazards are primarily caused by x-rays, gamma rays, high energy betas and neutrons, all forms of radiation (including low energy betas, gammas and alphas) can cause internal radiation exposures. Alpha particles create a high concentration of ions along their path, and can cause severe damage to internal organs and tissues when they are inhaled, ingested or are present on the skin. Once these particles get into the body, damage can occur since there is no protective dead skin layer to shield the organs and tissues. Internal exposures are not limited to the intake of large amounts at one time (acute exposure). Chronic exposure may arise from an accumulation of small amounts of radioactive materials over a long period of time. It is known that many substances taken into the body will accumulate in certain body organs, called target organs. For example, iodine will accumulate in the thyroid gland. When iodine is inhaled or ingested, the body cannot distinguish stable iodine from radioactive iodine; a significant portion of the inhaled iodine will be deposited in the thyroid gland within 24 hours. Other elements, such as calcium, strontium, radium and plutonium accumulate in the bones. Here, high doses to bones can occur over very long periods of time, since the body eliminates these materials very slowly once they are incorporated into the bone structure. The blood forming organs, such as the bone marrow, are very radiosensitive, since bone marrow cells are in the S-phase of mitotic activity more often than other cells. Hence, if there is a significant long-term exposure to radioisotopes, chronic diseases such as leukemia and/or osteosarcoma can occur. The induction time for the onset of these types of diseases is typically in excess of 20 years. A rule of thumb used to assist in biological risk assessment for radiation is that most mature cells are radioresistant; all immature cells are very radiosensitive. It is very important for radioactive materials users to be aware of the target organs for the nuclides they handle. Precautions may then be taken to prevent exposures.

24 Issue Date: Revision No.: 01 Page: 24 of Nature and Properties of Some Radioisotopes Used in Agriculture Phosphorus 32 ( 32 P) Physical Data Beta energy: MeV (maximum) MeV (average, 100% abundance) Physical half-life: 14.3 days Biological half-life: 1155 days Effective half-life: 14.1 days (bone) / 13.5 days (whole body) Specific activity: 285,000 Ci/gm Maximum range in air: 610 cm = 240 inches = 20 feet Maximum range in water/tissue: 0.76 cm = 1/3 inch Maximum range in Plexiglas/lucite/plastic: 0.61 cm = 3/8 inch Half-Value Layer (HVL): 2.00 mm (water/tissue) Radiological Data Critical organ (biological destination) (soluble forms): Bone Critical organs (insoluble forms or non-transportable 32 P compounds): Lung (inhalation) and G.I. tract/lower large intestine (ingestion) Routes of intake: Ingestion, inhalation, puncture, wound, skin contamination (absorption) External and internal exposure from 32 P Committed Dose Equivalent (CDE): 32 mrem/uci (ingested) (Organ Doses) 37 mrem/uci (puncture) 96 mrem/uci (inhaled/class W/lungs) 22 mrem/uci (inhaled/class D/bone marrow) Committed Effective Dose Equivalent (CEDE): 7.50 mrem/uci (ingested/wb) 5.55 mrem/uci (inhale/class D) mrem/uci (inhale/class W) Skin contamination dose rate: mrem/uci/cm 2 /hr. (7 mg/cm 2 or cm depth in tissue).

25 Issue Date: Revision No.: 01 Page: 25 of 61 Dose rate to basal cells from skin contamination of 1.0 uci/cm 2 (localized dose) = 9200 mrad/hr. Bone receives approximately 20% of the dose ingested or inhaled for soluble 32 P compounds. Tissues with rapid cellular turnover rates show higher retention due to concentration of phosphorous in the nucleoproteins. 32 P is eliminated from the body primarily via urine. Phosphorus metabolism; see 33 P Fact Sheet Shielding 3/8 inch thick Plexiglas/acrylic/lucite/plastic/wood. Do not use lead foil or sheets! Penetrating Bremsstrahlung x-ray will be produced! Use lead sheets or foil to shield Bremsstrahlung x-rays only after low density Plexiglas/acrylic/lucite/wood shielding Survey Instrumentation GM survey meter and a pancake probe. Low-energy NaI probe is used only to detect Bremsstrahlung x-rays. Liquid scintillation counter (indirect counting) may be used to detect removable surface contamination of 32 P on smears or wipes Dose Rates (from unshielded 1.0 mci isotropic point source) Distance Rads/hr 1.00 cm cm ft ,000 mrad/hr at surface of 1.0 mci 32 P in 1 ml liquid. 26,000 mrad/hr at mouth of open vial containing 1.0 mci 32 P in 1.0 ml liquid General Precautions Because it is a bone seeker, special precautions must be taken to minimize any chance of introducing into the body. Airborne contamination can be generated through drying (dust), rapid boiling, or expelling solutions through syringe needles and pipette tips, due to aerosols.

26 Issue Date: Revision No.: 01 Page: 26 of 61 Personnel radiation monitors (whole body and finger rings) are required when handling > 1.0 mci of 32 P at any time. Never work directly over an open container; avoid direct eye exposure from penetrating 32 P beta particles. Always wear a lab coat and disposable gloves when handling 32 P. Monitor personnel work areas and floors using a GM survey meter equipped with a pancake (beta) probe for surface contamination. Monitor for removable surface contamination by smearing or wiping where 32 P is used. Use low-density (low atomic number) shielding material to shield 32 P and reduce the generation of Bremsstrahlung x-rays. The following materials are low atomic number materials: Plexiglas, acrylic, lucite, plastic, wood, or water. Do NOT use lead foil, lead sheets, or other high density materials (metals) to shield 32 P directly. Materials with atomic number higher than that of aluminum (Z = 13) should NOT be used. Penetrating Bremsstrahlung x-rays will be generated in lead and other high density shielding material. Safety glasses or goggles are recommended when working with 32 P. Typical GM survey meter with pancake probe efficiency is ³45%. Typical liquid scintillation counter counting efficiency for 32 P (full window/maximum) > 85%. Typical detection limit of 32 P in urine specimens using a liquid scintillation counter = 1.1 E -7 uci/ml Phosphorus 33 ( 33 P) Physical Data Beta energy: MeV (maximum, 100% abundance) MeV (average) Physical half-life: 25.4 days Biological half-life: 19 days (40% of intake; 30% rapidly eliminated from body, remaining 30% decays) Effective half-life: 24.9 days (bone) Specific activity: 1,000-3,000 Ci/millimole Maximum beta range in air: 89 cm = 35 inches = 3 feet Maximum range in water/tissue: 0.11 cm = 0.04 inch Maximum range in plexiglas/lucite/plastic: cm = inch Half-Value Layer (HVL): 0.30 mm (water/tissue)

27 Issue Date: Revision No.: 01 Page: 27 of Radiological Data Critical organ (biological destination) (soluble forms): Bone marrow Critical organs (insoluble forms or non-transportable 33 P compounds): Lung (inhalation) and G.I. tract/lower large intestine (ingestion) Routes of intake: Ingestion, inhalation, puncture, wound, skin contamination (absorption) Internal exposure and contamination are the primary radiological concerns Committed Dose Equivalent (CDE): 0.5 mrem/mci (inhalation) Skin contamination dose rate: 2,910 mrem/hr/uci/cm 2 (7 mg/cm 2 or cm depth in tissue) Fraction of 33 P beta particles transmitted through the dead skin layer is about 14%. Tissues with rapid cellular turnover rates show higher retention due to concentration of phosphorus in the nucleoproteins. 33 P is eliminated from the body primarily via urine. Phosphorus metabolism: 30% is rapidly eliminated from body 40% has a 19-day biological half-life 60% of 33 P (ingested) is excreted from body in first 24 hrs Shielding Not required; however low density material is recommended, e.g., 3/8 inch thick plexiglas, acrylic, lucite, plastic or plywood Survey Instrumentation GM survey meter with a pancake probe. Liquid scintillation counting of wipes may be used to detect removable surface contamination Personnel Dosimeters Are not required, since they do not detect this low energy nuclide General Precautions Inherent volatility (STP): Insignificant Skin dose and contamination are the primary concerns. Drying can form airborne 33 P contamination. Monitor work areas for contamination, using smears or wipes to check for removable contamination Carbon 14 ( 14 C)

28 Issue Date: Revision No.: 01 Page: 28 of Physical Data Beta Energy: 156 kev (maximum) 49 kev (average) (100% abundance) Physical Half-Life: 5730 years Biological Half-Life: 12 days Effective Half-Life: 12 days (bound) Effective Half-Life: 40 days (unbound) Specific Activity: 4460 mci/gram Maximum Beta Range in Air: cm = 10 inches Maximum Beta Range in Water/Tissue: *0.28 mm = inches Maximum Range in Plexiglas/Lucite/Plastic: 0.25 mm = inches *Fraction of 14 C beta particles transmitted through dead layer of skin: At cm depth = 1% Radiological Data Critical Organ: Fat Tissue Routes of Intake: Ingestion, Inhalation, Skin Contact External exposure: Deep dose from weak 14 C beta particles is not a radiological concern Internal exposure & contamination: Primary radiological concerns Committed Dose Equivalent (CDE): 2.08 mrem/uci (ingested) (Fat Tissue) 2.07 mrem/uci (puncture) 2.09 mrem/uci (inhalation) Committed Effective Dose Equivalent (CEDE): 1.54 mrem/uci (ingested) Annual Limit on Intake (ALI)*: 2 mci (ingestion of labeled organic compound) 2000 mci (inhalation of carbon monoxide) 200 mci (inhalation of carbon dioxide) *[1.0 ALI = 2 mci (ingested C-14 organic compound) = 5,000 mrem CEDE]