02-637. Federal Policy on Use of Potassium Iodide (KI)

AGENCY:

Federal Emergency Management Agency (FEMA).

ACTION:

Notice of revised Federal policy.

SUMMARY:

The Federal Radiological Preparedness Coordinating Committee (FRPCC) has revised the 1985 Federal policy regarding the use of potassium iodide (KI) as a thyroidal blocking agent by emergency workers, institutionalized persons and the general public in the vicinity of nuclear power plants. This policy is for use by State ^[1] and local agencies responsible for radiological emergency planning and preparedness in the unlikely event of a major radiological emergency at a commercial nuclear power plant.

The Federal position is that KI should be stockpiled and distributed to emergency workers and institutionalized persons for radiological emergencies at a nuclear power plant and its use should be considered for the general public within the 10-mile emergency planning zone (EPZ) of a nuclear power plant. However, the decision on whether to use KI for the general public is left to the discretion of States and, in some cases, local governments.

EFFECTIVE DATE:

The modifications to this policy are effective January 10, 2002.

FOR FURTHER INFORMATION CONTACT:

Russell Salter, Chair, Federal Radiological Preparedness Coordinating Committee; [phone]; [e-mail].

SUPPLEMENTARY INFORMATION:

Background

This revised Federal policy on the use of potassium iodide as a thyroidal blocking agent for the general public in the vicinity of nuclear power plant 10-mile emergency planning zones is part of a Federal interagency effort coordinated by FEMA for the FRPCC. FEMA chairs the FRPCC and assumes the responsibility for this publication. The FRPCC is an interagency organization, with membership from 17 Federal agencies, established to coordinate all Federal responsibilities for assisting State and local governments in emergency planning and preparedness for peacetime nuclear emergencies.

The issue is addressed in terms of two components of the population that might require or desire potassium iodide use: (a) Emergency workers and institutionalized individuals, and (b) general population. With respect to emergency workers and institutionalized individuals, the Nuclear Regulatory Commission (NRC) and FEMA have issued guidance to State and local authorities, as well as to licensees of operating commercial nuclear power plants, in NUREG-0654/FEMA-REP-l, Rev.1. The NUREG and FEMA guidance recommends the stockpiling and distribution of KI to emergency workers and to institutionalized individuals for thyroidal blocking during emergencies. The guidance provides information regarding protective actions to be taken in the event of an incident at a commercial nuclear power plant. NUREG 0654 and the 1985 FRPCC KI policy recommend thyroidal blocking for emergency workers and institutionalized individuals because they are thought to be more likely than other members of the public to be exposed to the radioiodine in an airborne radioactive release.

The decision for using KI as a protective measure for the general public is left to the discretion of States, or in some cases, local governments, since these entities are ultimately responsible for the protection of their citizens. The policy guidance in this Federal Register notice is intended for State and local governments that, within the limits of their authority, should consider these recommendations in the review of their emergency plans and in determining appropriate actions to protect the general public. In making a decision whether to stockpile KI, the States should be aware that the Federal government believes that the use of KI is a reasonable and prudent measure as a supplemental protective action for the public.

Revision of the policy to include members of the public reflects lessons learned from the Chernobyl Nuclear Power Plant accident of 1986, both about the consequences of an accident and about the safety and efficacy of KI. The Chernobyl accident demonstrated that thyroid cancer can indeed be a major result of a large reactor accident. Based on the experiences from Chernobyl, young children are at greatest risk of thyroid cancer from radioactive iodine exposure. Moreover, although the Food and Drug Administration (FDA) declared KI “safe and effective” as long ago as 1978, the drug had never been deployed on a large scale until Chernobyl. The experience of Polish health authorities during the accident has provided confirmation that large-scale deployment of KI is safe.^[2] The Chernobyl experiences also led to wide-scale changes in international practice, specifically 1989 World Health Organization recommendations (updated in 1995 and 1999) and 1996 and 1997 International Atomic Energy Agency standards and guidance, which have led to the use of KI as a supplementary protective measure in much of Europe, as well as in Canada and Japan.

The NRC published changes to its emergency planning regulations at 66 FR 5441-5443, January 19, 2001. For States within the 10-mile planning zone of a nuclear power plant(s), the NRC believes that the use of KI is a reasonable and prudent measure as a supplement to sheltering and evacuation and in response to specific local conditions. The NRC requires consideration in the formulation of emergency plans as to whether to include the use of KI as a supplemental protective measure.

The FDA has evaluated the medical and radiological risks of administering KI for emergency conditions, has concluded that it is safe and effective, and has approved over-the-counter sale of the drug for this purpose. FDA has concluded that “* * * the effectiveness of KI as a specific blocker of thyroid radioiodine uptake is well-established as are the doses necessary for blockage. As such, it is reasonable to conclude that KI will likewise be effective in reducing the risk of thyroid cancer in individuals or populations at risk for inhalation or ingestion of radioiodines.” Since the FDA has authorized the nonprescription sale of KI, it may be available to individuals who, based on their own personal analysis, choose to have the drug immediately available. The FDA guidance is the definitive Federal guidance on medical aspects of KI prophylaxis.

Considerations

In making a decision whether to stockpile KI, States should be aware that the Federal government believes that the use of KI is a reasonable and prudent measure as a supplemental protective action for the public.

While there may be logistical difficulties in providing KI to the general public, any distribution scheme should take care to ensure that KI distribution does not impede or delay orderly evacuation. There also may be a few medical side effects in pre-distributing the drug to potentially affected individuals or in distributing the drug to the general public in a radiological emergency. Although the post-Chernobyl data from Poland revealed few serious medical side effects associated with this drug, this possibility cannot be discounted, especially in certain groups of people. For example, people who are allergic to iodine should not take KI.

Other considerations to be evaluated by the State and local authorities in deciding whether to institute a program for the use of KI by the general public include: (a) Whether KI should be distributed to the population before an accident occurs or as soon as possible after an accident occurs; (b) whether the risks of exposure to radioactivity will be lower if the evacuation of the general population is initiated—with or without the use of KI—or if the general population is sheltered and the administration of KI initiated; (c) how KI will be distributed during the emergency; (d) if KI is pre-distributed, what assumptions should be made about its actual availability and use in the event of an incident; (e) what medical assistance will be available for the individuals who may have some adverse reaction to KI; (f) how medical authorities will advise the population to take KI and under what circumstances this advice will be given, i.e., methods for public education, information and instruction; and (g) how the authorities will provide KI to transient populations.

In addition, there are some site-specific considerations to evaluate. Any decision by State and local authorities to use KI following a specific emergency should be based on the site environment and conditions for the specific operating commercial nuclear power plant and would include detailed plans for distribution, administration and medical assistance.

Revised Policy

In most cases, evacuation and in-place sheltering are considered adequate and effective protective actions for the general public in the event of a radiological emergency at a commercial nuclear facility. However, the inclusion of KI as a supplemental protective measure is beneficial in certain circumstances. It should be noted that the timely use of KI effectively reduces the radiation exposure of only the thyroid gland. While this is an important contribution to the health and safety of the individual, it is not as effective as measures that protect the total body of the individual from radioactivity. Both in-place sheltering and precautionary evacuations can reduce the exposure to the thyroid and total body. The use of KI for thyroidal blocking is not an effective means by itself for protecting individuals from the radioactivity in an airborne release resulting from a nuclear power plant accident and, therefore, should only be considered in conjunction with sheltering or evacuation, or a combination thereof.

While the use of KI can clearly provide additional protection in certain circumstances, the assessment of the effectiveness of KI and other protective actions and their implementation indicates that the decision to use KI (or other protective actions) should be made by the States and, when appropriate, local authorities on a site-specific basis. Thus, the decision on use of KI by the general public during an actual emergency is the responsibility of these authorities.

In summary, the Federal position is that KI should be stockpiled and distributed to emergency workers and institutionalized persons for radiological emergencies at a nuclear power plant, and its use should be considered for the general public within the 10-mile EPZ of a nuclear power plant. However, the decision on whether to use KI for the general public is left to the discretion of States and, in some cases, local governments.

This revised policy should not be taken to imply that the present generation of U.S. nuclear power plants is any less safe than previously thought. On the contrary, present indications are that nuclear power plant safety has steadily improved.

References

The following references are intended to assist State and local authorities in decisions related to use of KI:

1. Nuclear Regulatory Commission, final rule, Consideration of Potassium Iodide in Emergency Plans, 66 FR 5427, January 19, 2001.

2. World Health Organization, Guidelines for Iodine Prophylaxis Following Nuclear Accidents, 1999. Http://www.who.int/​environmental information/Information_resources/documents/Iodine/guide.pdf.

3. National Council on Radiation Protection and Measures (NCRP) Protection of the Thyroid Gland in the Event of Releases of Radioiodine. NCRP Report No. 55, August 1, 1977.

4. Food and Drug Administration (Health and Human Services), Potassium Iodide as a Thyroid-Blocking Agent in a Radiation Emergency, 43 FR 58798, December 15, 1978.

5. Food and Drug Administration, Notice, Guidance on Use of Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies; Availability, 66 FR 64046, December 11, 2001.

6. Report of the President's Commission on the Accident at Three Mile Island, National Technical Information Service, Springfield, VA 22161.

7. Federal Emergency Management Agency, Federal Policy on Distribution of Potassium Iodide Around Nuclear Power Sites for Use as a Thyroidal Blocking Agent, 50 FR 30258, July 24, 1985.

8. Nauman, J., and Wolff, J., Iodide Prophylaxis in Poland After the Chernobyl Reactor Accident: Benefits and Risks, American Journal of Medicine, Vol. 94, p. 524, May 1993.

9. International Atomic Energy Agency, International Basic Safety Standards for Protection Against Ionizing Radiation and for Safety of Radiation Sources. Safety Series No. 115, 1996.

Dated: January 2, 2002.

Joe M. Allbaugh,

Director.

Footnotes

1.  Consistent with FEMA initiative 4.0-4.4, Include Native American Tribal Nations in the REP Preparedness Process, references to State governments include Tribal governments.

2.  Nauman, J., and Wolff, J., Iodide Prophylaxis in Poland After the Chernobyl Reactor Accident: Benefits and Risks, American Journal of Medicine, Vol. 94, p. 524, May 1993.