U.S. NRC Blog

Transparent, Participate, and Collaborate

Throwback Thursday – Let There Be Light

lightbulbMore than 60 years ago this Saturday, a string of bulbs lit up courtesy of Argonne National Laboratory. What was the big deal? The electricity used to power the bulbs was generated by an experimental breeder reactor and was the first electricity produced using the heat of nuclear fission.

Photo from the Department of Energy

 

Keeping Tabs on Diablo Canyon’s Evolving Seismic Situation

Lara Uselding
Public Affairs Officer
Region IV

diabloThe NRC has added two items to the growing list of documents on seismic issues related to the Diablo Canyon Power Plant, near San Luis Obispo, Calif. Our Region IV office in Arlington, Texas, sent the plant operator, PG&E, an inspection report and our headquarters Office of Nuclear Reactor Regulation in Rockville, Md. sent PG&E a letter about the plant’s seismic hazard reevaluation due in March 2015.

The Region IV inspection report discusses the agency’s independent assessment of the operability determination completed by PG&E associated with its September report on the Shoreline and other faults near the plant. PG&E provided the report to the state under California Assembly Bill 1632. That bill required the report so the California Energy Commission could assess if California’s largest baseload power plants are vulnerable to a seismic event as those plants age.

The NRC did not request this analysis, but PG&E committed to keep us updated on any new information that would indicate the Shoreline fault is more energetic or capable than was presented in the January 2011 Shoreline Fault Report. PG&E further committed to provide the NRC with an interim analysis of any new Shoreline-related information before the post-Fukushima evaluations are due in March 2015.

Our regional review of PG&E’s operability determination indicates there is considerable design margin for the plant’s systems, structure, and components. The staff did not identify any concerns with PG&E’s determination that the plant is operable. The analysis adds to the evidence that the plant’s systems, structures, and components would function properly after an earthquake and not pose undue risk to public health and safety.

Our letter from headquarters confirms PG&E will incorporate the September report’s findings into its ongoing, post-Fukushima, full seismic re-analysis due in March 2015. The NRC believes this more rigorous analysis will provide the most accurate assessment of faults affecting the site.

The bottom line is that the effect of earthquakes has been extensively evaluated during the construction, licensing, and operation of the plant. Diablo Canyon’s systems, structures, and components are designed to withstand the area’s earthquakes and perform their safety functions.

Sixty-Plus Years of Reactor Safety Advice — and Still Going Strong

Ed Hackett
Executive Director
Advisory Committee on Reactor Safeguards

For as long as the United States has worked on commercial nuclear power plants, a group of experts has given regulators independent safety advice. Since Congress passed the Atomic Energy Act of 1954, the group’s been called the Advisory Committee on Reactor Safeguards.

The committee’s dozen or so members contribute decades of academic and/or practical experience in their specialties, which include risk assessment, health physics, accident analysis and several types of engineering. Past and present committee members have also lent their expertise to international regulators.

Members of the ACRS brief the NRC Commission.

Members of the ACRS brief the NRC Commission.

When there’s an opening on the committee, the Commission chooses a replacement from nominees among the leading experts in a given specialty. Committee members are supported by a small group of NRC staff who focus solely on the committee’s independent activities.

The full committee meets 10 times a year, spending several days each time to discuss a broad range of topics. For instance, this month’s meeting agenda included a developing new rule related to safety enhancements based on lessons learned from the Fukushima nuclear accident. Other meetings have covered reviews of new reactor licensing topics and operating reactor license renewal, as well as proposed facilities to create radioactive material for medical uses.

Committee members ask detailed questions of both NRC staff and industry representatives. If members feel an issue needs more explanation or analysis, they’ll keep asking questions and challenging assumptions until they’re satisfied. All of this interaction contributes to the committee’s opinions on the topics.

The committee’s conclusions, which are independent of the NRC staff’s work, are provided in formal letters to the NRC’s Chairman. The Commission takes the committee’s views into account when it considers licensing or policy matters. The committee also meets publicly with the Commission at least once a year to discuss major topics. The Commission uses the advice provided by the committee, in addition to the information provided by the NRC staff, in reaching its decisions on regulatory matters.

The committee also has an obligation to advise the U.S. Navy on its nuclear reactor program, as well as the Defense Nuclear Safety Board, which deals with Department of Energy-controlled facilities.

The committee does all of this work according to the requirements of the Federal Advisory Committee Act. This means all committee meetings are public, except when discussing sensitive information the NRC needs to protect. It also means the public can speak and present information to the committee. Keep an eye on our schedule to see when we’ll discuss something you’re interested in. Also, see our YouTube videeo on the ACRS.

Blue Topaz — The Irradiated Gemstone

Maureen Conley
Public Affairs Officer

There are a lot of great things about having a November birthday. The heat of summer is over but winter hasn’t set in so the weather can be magnificent. When the leaves are changing, the landscape is even more beautiful than in spring. It is the month of football, first frosts, harvesting the last of the summer vegetable garden, and my favorite holiday, Thanksgiving. But the one thing I never liked about my November birthday was my birthstone—topaz.

topaz 1Orange is just not my favorite color. I was always jealous of my family members, whose stones were so much prettier—amethysts in February, diamonds in April, and sapphires in September. Then one year I received as a gift some earrings with a beautiful blue stone. That was my introduction to blue topaz.

I was so happy to discover there was an alternative to the traditional orange topaz, I never thought to wonder what was behind the blue color. I figured topaz just came in blue, too.

Well it turns out blue topaz can be found in nature but it is very rare. Most blue topaz on the market has been exposed to radiation.

This is no cause for alarm. Irradiated gemstones are not harmful. Because they may be slightly radioactive immediately after their treatment, the NRC regulates the distribution of these products to ensure public health is protected. Any measureable radiation decays away within a couple months. Treated gemstones are set aside and are not sold until the radioactivity falls far below levels that can impact public health.

Distributors of irradiated gemstones must have an NRC license, which requires them to do radiological surveys before selling the gems. Their sophisticated instruments can detect very low levels of radiation. Once the radiation is low enough, no further licensing is required.

topaz 1Topaz is not the only gemstone treated with radiation to change its color. Diamonds, pearls and other gemstones are sometimes irradiated to change their color. In general, the longer stones are exposed to radiation, the deeper and more attractive the color.

Incidentally, not all radiation treatments applied to gemstones make them radioactive. If they are bombarded with neutrons, as in a nuclear reactor or accelerator, trace elements in the stones can become “activated” or radioactive. But gemstones can also be treated using gamma radiation (high-energy photons), which does not make them radioactive.

If your holiday shopping list includes jewelry this year, don’t be afraid of irradiated gemstones. The NRC license ensures they don’t reach the market until they are completely safe.

Throw Back Thursday — Haddam Neck

haddamneckIn this photo, the 402-ton nuclear reactor vessel head for the Haddam Neck nuclear power plant passes the New York City skyline on March 29, 1966. Haddam Neck was a pressurized water reactor located in Meriden, Conn. When was it shut down? Photo courtesy of the former Atomic Energy Commission.

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