Nuclear Leaks: The Back Story the NRC Doesn’t Want You to Know about Palo Verde

UCS, DAVE LOCHBAUM, DIRECTOR, NUCLEAR SAFETY PROJECT | JUNE 14, 2017, As described in a recent All Things Nuclear commentary, one of two emergency diesel generators (EDGs) for the Unit 3 reactor at the Palo Verde Nuclear Generation Station in Arizona was severely damaged during a test run on December 15, 2016. The operating license issued by the Nuclear Regulatory Commission (NRC) allowed the reactor to continue running for up to 10 days with one EDG out of service. Because the extensive damage required far longer than 10 days to repair, the owner asked the NRC for permission to continue operating Unit 3 for up to 62 days with only one EDG available. The NRC approved that request……..http://allthingsnuclear.org/dlochbaum/back-story-on-palo-verde

June 16, 2017 Posted by Christina Macpherson | safety, USA | Leave a comment

Niagara region to learn about transport of nuclear waste, and its dangers

Expert to speak on nuclear transporting https://www.niagarathisweek.com/news-story/7369046-expert-to-speak-on-nuclear-transporting/  Niagara District Council of Women welcome Gordon Edwards to Lincoln town hall Jun 13, 2017  by Luke Edwards  Grimsby Lincoln News A U.S. judge has ruled the Department of Energy can proceed with its plan to import 6,000 gallons of liquid nuclear waste from Canada. The proposed route goes through Niagara.

June 14, 2017 Posted by Christina Macpherson | safety, USA | Leave a comment

Oyster Creek Reactor: Bad Nuclear Vibrations 

Union of Concerned Scientists DAVE LOCHBAUM, DIRECTOR, NUCLEAR SAFETY PROJECT | JUNE 13, 2017, The Oyster Creek Nuclear Generating Station near Forked River, New Jersey is the oldest nuclear power plant operating in the United States. It began operating in 1969 around the time Neil Armstrong and Buzz Aldrin were hiking the lunar landscape.

Oyster Creek has a boiling water reactor (BWR) with a Mark I containment design, similar to the Unit 1 reactor at Fukushima Daiichi. Water entering the reactor vessel is heated to the boiling point by the energy released by the nuclear chain reaction within the core (see Figure 1). The steam flows through pipes from the reactor vessel to the turbines. The steam spins the turbines connected to the generator that produces electricity distributed by the offsite power grid. Steam discharged from the turbines flows into the condenser where it is cooled by water drawn from the Atlantic Ocean, or Barnegat Bay. The steam vapor is converted back into liquid form. Condensate and feedwater pumps supply the water collected in the condenser to the reactor vessel to repeat the cycle………

Bad Vibrations

In the early morning hours of November 20, 2016, the operators at Oyster Creek were conducting the quarterly test of the turbine control system. With the reactor at 95 percent power, the operator depressed a test pushbutton at 3:26 am per the procedure. The plant’s response was unexpected. The positions of the control valves and bypass valves began opening and closing small amounts causing the reactor pressure to fluctuate. Workers in the turbine building notified the control room operators that the linkages to the valves were vibrating. The operators began reducing the reactor power level in an attempt to stop the vibrations and pressure fluctuations.

The reactor automatically shut down at 3:42 pm from 92 percent power on high neutron flux in the reactor. Workers later found the linkage for control valve #2 had broken due to the vibrations and the linkage for control valve #4 had vibrated loose. The linkages are “mechanical arms” that enable the turbine control system to reposition the valves. The broken and loosened linkages impaired the ability of the control system to properly reposition the valves.

These mechanical malfunctions prevented the EHC system from properly controlling reactor pressure during the test and subsequent power reduction. The pressure inside the reactor vessel increased. In a BWR, reactor pressure increases collapse and shrink steam bubbles. Displacing steam void spaces with water increases the reactor power level. When atoms split to release energy, they also release neutrons. The neutrons can interact with other atoms to causing them to split. Water is much better than steam bubbles at slower down the neutrons to the range where the neutrons best interact with atoms. Put another way, the steam bubbles permit high energy neutrons to speed away from the fuel and get captured by non-fuel parts within the reactor vessel while the water better confines the neutrons to the fuel region.

The EHC system’s problem allowed the pressure inside the reactor vessel to increase. The higher pressure collapsed steam bubbles, increasing the reactor power level. As the reactor power level increased, more neutrons scurried about as more and more atoms split. The neutron monitoring system detected the increasing inventory of neutrons and initiated the automatic shut down of the reactor to avoid excessive power and fuel damage.

Workers attributed the vibrations to a design flaw. A component in the EHC system is specifically designed to dampen vibrations in the tubing providing hydraulic fluid to the linkages governing valve positions. But under certain conditions, depressing the test pushbutton creates a pressure pulse on that component. Instead of dampening the pressure piles, the component reacts in a way that causes the hydraulic system pressure to oscillate, creating the vibrations that damaged the linkages.

The component and damaged linkages were replaced. In addition, the test procedure was revised to avoid performing that specific portion of the test when the reactor is operating. In the future, that part of the turbine valve test will be performed during an outage.

Vibrations Re-Visited

It was not the first time that Oyster Creek was shut down due to problems performing this test. It wasn’t even the first time this decade…..http://allthingsnuclear.org/dlochbaum/oyster-creek-bad-vibrations

June 14, 2017 Posted by Christina Macpherson | safety, USA | Leave a comment

Fire danger of America’s nuclear waste pools – underestimated by Nuclear Regulatory Commission (NRC)

Study: US NRC Relied On Faulty Analysis To Justify Refusal To Adopt Catastrophic Nuclear Waste Fire Safety Measures, Clean Technica, June 11th, 2017 by James Ayre , A new study from Princeton University and the Union of Concerned Scientists has revealed that the US Nuclear Regulatory Commission (NRC) relies on faulty analysis to “justify its refusal to adopt a critical measure for protecting Americans from the occurrence of a catastrophic nuclear-waste fire at any one of dozens of reactor sites around the country.”

While the nuclear fallout from such an incident could contaminate an area twice the size of New Jersey, force the relocation of around 8 million people, and cause trillions of dollars in damages, the NRC apparently sees no issue with the current lack of safeguards — and is content with using faulty justifications for cover. I wonder why?

Frank von Hippel, a co-author of the new paper and a senior research physicist at Princeton’s Program on Science and Global Security (SGS), commented: “The NRC has been pressured by the nuclear industry, directly and through Congress, to low-ball the potential consequences of a fire because of concerns that increased costs could result in shutting down more nuclear power plants. Unfortunately, if there is no public outcry about this dangerous situation, the NRC will continue to bend to the industry’s wishes.”

Catastrophic nuclear fires like those mentioned above could be triggered at many of the nuclear power plants in the US through a variety of mechanisms, whether by large earthquakes or terrorism. The thing about this, though, is that simple regulatory measures could greatly reduce the likelihood and extent of such events — the problem is simply that they drive up costs and are thus unwanted by those in the industry and associated with it.

Since there are a number of nuclear energy proponents that comment on this site from time to time, I’ll use this opportunity to note that my main objection with nuclear is simply that there’s no way to separate it from human nature/stupidity. ……

Something that should be realized here is that while such an event would lead to total damages of around $2 trillion, according to the researchers, the nuclear industry itself would only be liable to cover around $13.6 billion, owing to the Price Anderson Act of 1957. In other words, as with the banking crisis, US tax payers would again be on the hook.

The authors of the new work note that states that provide nuclear subsidies can probably force the hands of some operators, requiring them to enact the suggested changes by threatening to withhold funding.

Co-author Edwin Lyman, a senior scientist at the Union of Concerned Scientists, concludes that: “In far too many instances, the NRC has used flawed analysis to justify inaction, leaving millions of Americans at risk of a radiological release that could contaminate their homes and destroy their livelihoods. It is time for the NRC to employ sound science and common-sense policy judgments in its decision-making process.”

The new research is detailed in a paper published in the journal Science.  https://cleantechnica.com/2017/06/11/study-us-nrc-relied-faulty-analysis-justify-refusal-adopt-catastrophic-nuclear-waste-fire-safety-measures/

June 12, 2017 Posted by Christina Macpherson | safety, USA | Leave a comment