TMI Update: Jan 14, 2024

From the U.S. Nuclear Regulatory Commission:

This year has seen a dramatic increase in a question people regularly ask the Nuclear Regulatory Commission: “What magnitude earthquakes are U.S. nuclear power plants designed to withstand?” The answer, however, does not include a specific “magnitude.”

The NRC requires U.S. reactors to withstand a predicted level of ground motion, or acceleration, specific to a given site. Ground acceleration is measured in relation to “g,” the acceleration caused by Earth’s gravity.

An earthquake’s magnitude, often described on the Richter scale, is an expression of how much energy the quake released. It’s not possible to transform a given magnitude alone to ground acceleration at a site. Several important factors affect the relationship between an earthquake’s magnitude and associated ground acceleration, including the distance from the earthquake, the depth of the quake and the site’s local geology (i.e., hard rock or soil). A small earthquake close to a site could therefore generate the same peak ground acceleration as a large earthquake farther away.

The NRC’s requirements call for a nuclear power plant’s design to account for ground acceleration that is appropriate for its location, given the possible earthquake sources that may affect the site and the makeup of nearby faults, etc. Existing U.S. plants were designed on a “deterministic” or “scenario earthquake” basis. In other words, examination of an area’s seismological history provides an understanding of the largest earthquake and associated ground acceleration expected at a plant site.

Later this year, the agency expects to provide existing plants a seismic analysis tool based on work related to applications for new plants, along with the latest information on earthquake sources, so that the plants can perform an updated review. Applications for new nuclear power plants have taken a “probabilistic” approach to determining seismic hazards, looking at a wide range of possible quakes from sources that could affect a given site. The NRC has spent several years examining how these newer techniques can be used to re-evaluate existing nuclear power plant sites.

From NRC News:

The Nuclear Regulatory Commission will present information during the National Academy of Sciences’ (NAS) fifth committee meeting on the NRC-sponsored study, “Analysis of Cancer Risks in Populations Near Nuclear Facilities: Phase 1.” The meeting’s public session will run from 1:20 p.m. – 5 p.m. on Monday, Aug. 29, at the Pew Charitable Trusts Conference Center, 901 E St., NW in Washington, D.C.

The NRC will outline potential next steps for the study and describe the agency’s public outreach and communications efforts. NRC staff will also be available to answer committee member questions. The Environmental Protection Agency will also present information to the committee. The public is welcome to attend and will have the opportunity to comment prior to the end of the meeting. The NAS asks members of the public to register for the meeting, and the NAS website has additional details, although they are subject to change. General questions on the study can be sent via e-mail to: crs@nas.edu.

The NAS project will update the 1990 U.S. National Institutes of Health – National Cancer Institute (NCI) report, “Cancer in Populations Living Near Nuclear Facilities.” The NRC uses the 1990 NCI report as a primary resource when communicating with the public about cancer mortality risk in counties that contain or are adjacent to nuclear power facilities. In the new study, the NRC is asking the NAS to evaluate cancer diagnosis rates, in addition to mortality risk, for populations living near decommissioned, operating and proposed NRC-licensed nuclear facilities. Phase 1 of the NAS study will determine whether a technically defensible approach to meet the goals of the study request is feasible – and if so, the approach will be developed using scientifically sound processes for evaluating cancer risk that could be associated with nuclear facilities.

Exelon Nuclear

FOR IMMEDIATE RELEASE

KENNETT SQUARE, PA. (August 23, 2011) - None of Exelon Nuclear's four Mid-Atlantic nuclear energy stations was affected by this afternoon’s seismic activity in Virginia, and all continue to operate safely at this time. An “Unusual Event” was declared at each of the stations following the seismic activity, in accordance with plant procedures: Peach Bottom Atomic Power Station, Three Mile Island Generating Station and Limerick Generating Station in Pennsylvania, and Oyster Creek Generating Station in New Jersey.

Three Mile Island Nuclear Station, Unit 1 – Issuance of Amendment Re: Relocation of Equipment Load List From Technical Specifications to Updated Final Safety Analysis Report (TAC No. ME4732)
 
Download ML112150486
 

Three Mile Island Nuclear Station, Unit 1 – Issuance of Amendment Re: Relocation of Equipment Load List From Technical Specifications to Updated Final Safety Analysis Report (TAC No. ME4732)
 
Download ML112150486
 

New Data Supports Previous Fairewinds Analysis, as Contamination Spreads in Japan and Worldwide from Fairewinds Associates on Vimeo.

From Majirox News:

Parts of the 20-kilometer (12.42 mile) Evacuation Zone around the radiation-leaking Fukushima Daiichi nuclear plant are close to being declared uninhabitable and the ban on entering the area maintained, possibly for decades, according to the Yomiuri newspaper on Aug. 21.

Prime Minister Naoto Kan is poised to explain the situation to local government leaders from the affected leaders and apologize for evacuation from the area becoming long-term rather than temporary.

Excess radiation dozens of times greater than the acceptable annual safety level in parts of the zone is behind the moves, which thwart national government plans to reopen the area by January next year upon achieving a cold shutdown of the plant, which went into meltdown after the March 11 earthquake and tsunami that hit the Tohoku Region.

Read more

To Whom It May Concern:
 
Attached are the Minutes of the June 23, 2011 Susquehanna River Basin Commission meeting.  Please let me know if you have any problems opening the document, or wish to be removed from this email list.
 
Thank you for your interest.
 
Ava A. Stoops
 

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PRESS RELEASE
FOR IMMEDIATE RELEASE: August 19, 2011
CONTACT:  Linda Gunter, Beyond Nuclear, 301.455.5655
         
Nuclear Regulatory Commission recommends further review of Beyond Nuclear petition for emergency enforcement actions at Fukushima-style US reactors

[Takoma Park, MD]  The U.S. Nuclear Regulatory Commission (NRC) has accepted several emergency actions for further agency review that were requested in a petition filed by Beyond Nuclear on April 13, 2011. The Beyond Nuclear petition seeks to suspend the operation of the dangerous and seriously flawed General Electric Mark I Boiling Water Reactors, 23 of which still operate around the U.S. and which are almost identical to the Fukushima reactors that melted down in Japan. The petition was co-signed by national and regional anti-nuclear groups as well as more than 5,000 individuals.
The Beyond Nuclear petition to the NRC asks that the Mark I reactors cease operations until several emergency actions are taken. The actions accepted by the federal agency for the further review include;  1) the NRC revoke the 1989 prior approval for all GE Mark I operators to “voluntarily” install the same experimental hardened vent systems on flawed containment structures that the Fukushima catastrophe demonstrates to have a 100% failure rate and; 2) that the agency immediately issue Orders requiring all U.S. Mark I operators to promptly install dedicated emergency back-up electrical power to ensure reliable cooling systems for the densely packed spent fuel pools. The GE BWR fuel pools are located at the top of the reactor building and currently do not have backup power if offsite and on-site electrical power were lost simultaneously.
“Fukushima demonstrates that a nuclear catastrophe can result from these same fundamental flaws in the Mark I reactors operating in the United States,” said Paul Gunter, director of the Reactor Oversight Project at Beyond Nuclear. “We are spotlighting these dangerous reactors to test the NRCs’ willingness to take enforcement action to protect public safety rather than protect the nuclear industry bottom line,” he said.
On July 19, 2011, NRC released its own “Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident.”  While the Task Force addresses the same two action items found in the Beyond Nuclear petition that were accepted by the review board, the Task Force’s conclusions are considerably weaker.
First, where NRC task force recommendation 5 states that the agency consider issuing an Order to Mark I operators to upgrade hardened vent systems on the containment, the public petitioners have requested the agency revoke all prior approval of the “voluntary” installation of the controversial venting system. The vents were seen to fail at Fukushima and are only in place to save the containment which is too weak to withstand a severe accident. The containments were retrofitted in the 1990’s to instead temporarily vent explosive gas, steam pressure and radioactivity to the outside atmosphere to save the containment component.
“Given the catastrophic failure demonstrated at Fukushima, these same designs should not be allowed to operate with experimental vents on containment,” said Gunter, “The GE  reactor was originally licensed with the claim of a ‘leak tight’ containment so this after-thought of  installing a vent for accident conditions is in fact a violation of that same license,” he said.
Scott Portzline, security consultant to Three Mile Island Alert, Harrisburg PA said, ”The NRC’s Task Force on Fukushima has also recommended that the Mark II design reactors, like the one at Limerick PA, also be ordered to change over to a reliable vent system. The Peach Bottom Reactors would be affected by such an order since they are of Mark I design.”
In its petition, Beyond Nuclear additionally asked that the NRC then provide the public with full hearing rights to first independently review any further experimental modifications to the acknowledged weaker and substandard Mark I containment system.
Secondly, where NRC task force recommendation 7 states that emergency back-up power should be provided to ensure make-up for water boiled off of overheated spent fuel pools following loss of offsite power, the petitioners’ request that reliable back-up power be provide to assure reliable cooling to prevent the pools from boiling off.  The petitioners remain concerned about the unintended consequences of condensation from a spent fuel pool boil off affecting safety-related systems like electrical circuits and sump systems.
The NRC review board further recommended that the agency “reject” in part Beyond Nuclear’s requested actions for any further review to include; 1) “Immediately suspend operating licenses of all GE BWR Mark I units pending full NRC review with independent expert and public participation from the affected emergency planning zone communities,” and; 2) “Conduct public meetings within each of the ten-mile emergency planning zone for each GE BWR site for the purpose of receiving public comment and independent expert testimony regarding the reliability of hardened vent system or direct torus vent system.”
Beyond Nuclear and the co-petitioners will be provided an additional public meeting before the NRC’s Petition Review to present supplemental material and challenge agency recommendations to reject requested emergency actions. The date for that meeting has not been established.
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