ML19182A174
| ML19182A174 | |
| Person / Time | |
|---|---|
| Issue date: | 07/25/2019 |
| From: | Michael Scott NRC/NSIR/DPR |
| To: | Casey M US Environmental Protection Agency, Region 8 |
| Patricia Milligan | |
| References | |
| Download: ML19182A174 (5) | |
Text
July 25, 2019 Michael S. Casey, PhD Director, Technological Hazards Division Federal Emergency Management Agency - Area 8 400 C Street, SW Washington, DC 20024
SUBJECT:
REPLENISHMENT OF POTASSIUM IODIDE FOR THE PILGRIM NUCLEAR POWER STATION PLUME EXPOSURE PATHWAY EMERGENCY PLANNING ZONE
Dear Dr. Casey:
The purpose of this letter is to inform the Federal Emergency Management Agency (FEMA) of the views of the U.S. Nuclear Regulatory Commission on replenishment of potassium iodide (KI) for areas of Massachusetts surrounding the Pilgrim Nuclear Power Station (PNPS).
Pilgrim permanently ceased operations on May 31, 2019. By letter dated June 10, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19161A033), pursuant to 10 CFR Section 50.82(a)(1)(ii), Entergy (the licensee) certified that the fuel was permanently removed from the Pilgrim reactor vessel and placed in the spent fuel pool on June 9, 2019. Entergy further acknowledged that upon docketing of this letter, the Pilgrim 10 CFR Part 50 license no longer authorizes operation of the reactor or emplacement or retention of fuel in the reactor vessel.
The current potassium iodide stock for the Pilgrim plume exposure pathway emergency planning zone (EPZ) expires in December 2019. As you know, KI is a protective measure to minimize uptake in the thyroid gland of radioactive iodine following the highly unlikely release of large amounts of radioactive materials from an operating nuclear power plant. Radioactive iodine is a byproduct resulting from nuclear fission; once fission stops, production of radioactive iodine stops. The isotope of concern, I-131, has a short half-life (8 days), and after 10 half-lives have elapsed the radioactive iodine is effectively decayed away. Due to the permanent shutdown of PNPS on May 31, 2019, essentially no radioactive iodine (I-131) will remain in the spent fuel at Pilgrim by the time the current KI stock in the area expires. Therefore, KI will be unnecessary and inappropriate as a protective measure in the Pilgrim EPZ, and the expired KI will not be replenished.
Enclosure:
Technical Basis For Termination Of Potassium Iodine Program For Shutdown Reactors
Dr. Casey Consistent with recent Commission-approved exemptions for decommissioning power reactors, Entergy has applied to the NRC for exemptions to emergency planning requirements, which includes eliminating the requirement for a range of protective actions for the public within the plume exposure pathway EPZ.
If approved by the Commission, the requested exemptions will not be effective until April 2, 2020 (10 months after permanent cessation of power operations). For the period between expiration of the existing KI stock and removal of offsite emergency planning requirements, the NRC requests that FEMA not evaluate use of KI by offsite officials. Additional technical details regarding the necessity of potassium iodide for decommissioned reactors are contained in the attachment.
Sincerely,
/RA/
Michael L. Scott, Director Division of Preparedness and Response Office of Nuclear Security and Incident Response cc:
Jack Priest Jr.
Director-Radiation Control Program Massachusetts Dept. of Public Health 529 Main Street, Suite 1M2A Charlestown, MA 02129 John Giarrusso Jr.
Planning and Nuclear Section Chief Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702 Steve Colman, National Preparedness Division FEMA Region 1 99 High St.
Boston, MA 02110
Enclosure TECHNICAL BASIS FOR TERMINATION OF POTASSIUM IODIDE PROGRAM FOR SHUTDOWN REACTORS NRC Replenishment Commitment The NRC implemented its potassium iodide (KI) tablet distribution program in 2001 to support the rule change to 10 CFR 50.47(b)(10), which required States to consider KI as part of their range of protective actions. In 2009 the Commission directed the staff in the Staff Requirements Memorandum (SRM) to SECY-09-0041, Recommendation for Future Replenishment of Potassium Iodide (ADAMS Accession No. ML090970150), to provide KI tablets to affected States that request them and replenishing KI tablet stockpiles upon States requests consistent with the tablet shelf life.
Potassium Iodide and Emergency Preparedness Before radioactive iodine from the nuclear fuel of an operating nuclear power reactor can reach the environment, extensive damage must occur to the fuel elements in the reactor core with additional damage to the containment structure enclosing the reactor. Most potential accidents related to an operating reactor are no longer possible because the reactor has permanently ceased power operations and the fuel has been permanently removed from the reactor vessel to the spent fuel pool. The only postulated design basis accident (DBA) that would remain applicable to the permanently defueled Pilgrim Nuclear Power Station (PNPS) that could contribute a significant dose would be a fuel handling accident (FHA) in the Reactor Building, where the SFP is located. In these analyses, the doses from an FHA in the early stages after shutdown are dominated by the isotope Iodine 131, which has a short half-life (8 days). As such, I-131 is only a concern with respect to the fuel in an operating nuclear power plant or with fuel from a reactor core that has recently been shut down. After 10 half-lives, less than 0.1% of the initial quantity of radioactive iodine will remain. Therefore, spent nuclear fuel stored in the spent fuel pool at a nuclear power plant is free of significant radioiodine within approximately 4 months after shutdown of the reactor. Spent nuclear fuel that is stored in casks on a storage pad outside a nuclear-reactor building is old fuel that has been kept so long that it does not contain short-lived radioisotopes.
The licensee has requested from the NRC exemptions from certain emergency planning (EP) requirements of Part 50, Domestic Licensing of Production and Utilization Facilities. In support of this request, the licensee submitted the required analyses per Interim Staff Guidance (ISG) document NSIR/DPR-ISG-021. These analyses meet the ISG criteria to justify elimination of the requirement on the licensee to maintain the plume exposure pathway and ingestion pathway emergency planning zones (EPZs) and formal offsite radiological emergency preparedness (REP) plans and preparedness. The effective implementation date of the revision to the emergency plan, based on these analyses, is no earlier than 10 months after shutdown (April 2, 2020).
1 NSIR/DPR-ISG-02, Emergency Planning Exemption Requests for Decommissioning Nuclear Power Plants, dated May 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14106A057
PNPS permanently ceased operations on May 31, 2019. By the end of September 2019, Iodine-131 has decayed at least 10 half-lives and after that elapsed time there would be essentially no thyroid dose from an FHA. The current NRC supplied KI stockpile expires in December 2019. The NRC recognizes that the requested exemption from offsite emergency plans does not take effect until April 2, 2020; however, without the presence of radioactive iodine in a release there is no need to consider KI as part of the suite of protective actions during this period (January - April 2020).
ML19182A174 OFFICE NSIR/DPR OGC NSIR:D NAME P. Milligan L. Sheldon Clark M. Scott DATE 07/22/19 07/19/19 07/25/19