A Monday Quiz — A Blue Glow

The Advanced Test Reactor at Idaho National Laboratory uses plate type fuel in a clover leaf arrangement. The blue glow around the core is known as Cherenkov radiation. Courtesy of Idaho National Laboratory.

This Advanced Test Reactor runs tests that determine how fuels and materials react when bombarded by streams of neutrons and gamma rays under a variety of pressure and temperature conditions. Information that would normally require years to gather from normal reactor operations can be obtained in a matter of weeks or months. The primary “customer” of the reactor is the Naval Nuclear Propulsion Program.

The NRC licenses 31 research and test reactors in 21 states (as of 2014); eight research reactors are being decommissioned. We also license the operators and conduct some 50 inspections each year. DOE, however, regulates this particular test reactor.


Where is this test reactor located?
What scientist (and Nobel Prize winner) gave his name to the blue glow seen in this photo?


Author: Moderator

Public Affairs Officer for the U.S. Nuclear Regulatory Commission

22 thoughts on “A Monday Quiz — A Blue Glow”

  1. Reactor photo is from the Advanced Test Reactor at Idaho National Laboratory.

  2. Some additional information on the security Design Basis Threat (DBT) at nuclear facilities including test/research reactors:
    Terrorists Read & Heed!
    Thanks to successful nuclear industry lobbying efforts with our dysfunctional US Congress and our lax nuclear industry regulator (the NRC), the following security-threat restrictions have been placed on all our US nuke power plants (NPPs):
    • Terrorists can only use a half-dozen or so dirt-bags to attack a NPP. This even though 19 scum-bags attacked us on 9/11. This conveniently allows nuke plants to only have a 10-member armed response force at any time.
    • Only one or two (at the most) so-called “insiders” can work with and support this terrorist attack force. This even though this restriction does not comport with a conspiracy of insiders which is a common phenomenon in past thefts from highly-secure, non-nuclear facilities.
    • A nuclear plant owner does not have to defend against an aircraft attack. This is left to other federal agencies. The FAA wanted to have a 24/7 no-flight zone around all US nuclear plants. Thanks to resistance from the aircraft industry and their bottom line, the FAA only requires such a no-fly zone if the national security threat level is raised. Of course an additional good security measure, also never adopted, would be to alter approach and landing patterns at airports near nuke plants (and there are many of them) to vector aircraft away from these plants. That way additional response time would be available in case an airliner was high jacked with the intent of crashing it into a nuke plant. An aircraft does not have to actually penetrate and probably would not be able to penetrate the robust containment structure surrounding a nuke plant’s reactor. But the huge amount of fuel in a commercial airliner would ignite a raging fire in the building surrounding the reactor in the containment building, torching all instrument and control connections and destroying safety systems including pumps, valves, and power supplies. Spent fuel damage and reactor core melt would soon follow.
    • The terrorist attack group cannot possess or use RPGs or 50-caliber sniper rifles, even though these two weapons are commonly used by terrorists. These weapons were originally on a list of weapons provided by the intelligence staff. When the NRC finalized its requirements it eliminated those two weapons, reflecting nuclear industry input. This decision was based, it is alleged, on pressure from the nuclear industry to keep costs down.
    I am sure terrorists will restrict themselves accordingly. Just like they have taken our major dams off their hit list after the feds posted a huge warning sign on each one of those vulnerable dams. The warning can be easily seen from the air and says words to the effect that this dam is an off-limit target in the event of war.

  3. Additionally “The NRC is inhibited from imposing strict regulations on research reactors by the U.S. Atomic Energy Act, which allows the NRC to impose ‘only such minimum amount of regulation. . . as will permit the Commission to fulfill its obligations under this Act . . .’” As a result, research reactors generally do not have to protect against radiological sabotage or provide an armed response to an attack.
    How convenient!

  4. Excerpt from “Protecting US Nuclear Facilities from Terrorist Attack” by Kirkham & Kuperman 8-15-13
    Note: I have placed text in “bold” when references are made to test/research reactors. Sorry my bold text did not come thru. Please check the fourth and last paragraphs especially. Thanks.

    The Design Basis Threat (DBT)

    “The NRC views nuclear security as a balancing of risks and costs, with the understanding that achieving a “zero” level of risk is impossible. Since 2001, the U.S. nuclear industry has spent over $2 billion on security enhancements to their physical protection systems. However, it is difficult to know if those enhancements have been adequate. As Matthew Bunn writes, “no one really knows how clever a plan, with how many attackers, what weapons, or what capabilities, terrorists might be able to bring to bear. The NRC ostensibly attempts to estimate that through its DBT. But criticism of the NRC’s DBT focuses on the number of adversaries, their weapons, and the exclusion of air attacks and some sea attacks.

    Prior to the revisions following September 11, 2001, the NRC’s DBT assumed one team of three individuals, aided by a passive insider who provided information but did not participate in the attack. The numbers were kept relatively low because intelligence agencies generally assumed that they themselves were capable of detecting conspiracies of more than a few members. This assumption was proven wrong by the events of 9/11 when 19 hijackers, acting in four independent teams, planned and executed a plot without prior detection by authorities.

    Although the details of the revised DBT are classified, one source reports that the assumed number of attackers was only increased to “less than double the old figure and a fraction of the size of the 9/11 group” of 19 hijackers. Another source specifies it as “five or six well-armed terrorists, possibly working in conjunction with an insider or two. This number reflects the NRC’s assumption that only one terrorist cell would attack a plant. The Nuclear Energy Institute (NEI), a nuclear industry lobbying group, defends this assumption on grounds that the 9/11 attacks represent four separate attacks of three or four terrorists each, not an attack by nineteen terrorists. Critics say this does not adequately represent the present threat, which should take into account the size of the entire 9/11 attack force, and at a minimum posit an attack from a “squad size” of adversaries (12-14 personnel).

    The insider threat is downplayed in two ways, say critics. First, although the revised DBT reportedly does consider one or two active (i.e., violent) insiders working with outside attackers, it does not contemplate a larger conspiracy of insiders, which is a common phenomenon in past thefts from highly secure, non-nuclear facilities. Second, when the NRC evaluates the adequacy of security measures at power reactors by requiring force-on-force tests, these exercises may not simulate even the tiny number of active insiders contemplated by the revised DBT. (A related criticism is that at research reactors licensed by the NRC, no force-on-force tests at all are conducted, even if the sites contain HEU (Highly Enriched Uranium), because such facilities are not required to defend against the DBT.) Thus, according to critics, the U.S. government both underestimates the insider threat and fails to assure protection against even that underestimated threat. But a U.S. nuclear industry representative has responded, regarding the force-on-force tests at power reactors, that “in the exercises we assume there will be insider support. We provide adversaries with inside information. This suggests that the tests do contemplate at least a passive insider.

    The NRC also takes a graded approach to security by requiring a higher level of protection for sites considered to have greater potential consequences from an attack. As a result, the DBT for theft of nuclear material assumes a greater threat than for radiological sabotage. Additionally, the NRC believes terrorists require greater capabilities to commit theft than sabotage, since theft necessarily implies defeating security measures to both enter and exit the facility. Sabotage by a suicidal attacker only requires defeating security measures to enter.

    Until the NRC requires licensees to guard against a 9/11-sized attack force, critics argue, the NRC is effectively depending on protection by other government forces, but these other forces may not be available or sufficient. For example, according to the Project on Government Oversight (POGO), timelines of the DOE indicate that it would take approximately 1.5 to 2 hours for a SWAT team to respond and fully engage against an on-site attack, which could be too late to avert theft or sabotage. At several NRC licensed research reactors that still use HEU fuel, the primary threat is theft. At power reactors and other research reactors, the main threat is radiological sabotage. The Union of Concerned Scientists projects that a team of well-trained terrorists, after gaining access to a power reactor site, could cause enough damage within a matter of minutes to produce a core meltdown that could disperse enormous amounts of radiation.”

  5. Please check out the article at this link:
    This article was published a couple of years after 9/11. The title of the article is “Research Reactor Vulnerability to Sabotage by Terrorists”. I know that power reactor security has been considerably upgraded since 9/11. Has research and test reactor security been considerably upgraded as well? This is very important as these test reactors are located in areas of high population (for example university campuses).
    Are these test reactors manned 24/7 by not only operators but by armed security personnel as well?

    Nuke Puke

  6. Got some sharp folks on this blog. I did not know the location of the test reactor but I do recall the name Cerenkov radiation. Is it sometimes also called “braking radiation”? I think that is the English translation of the German word “Bremsstrahlung”. Is it called braking radiation as it occurs when a particle travelling near the speed of light is slowing down in a medium where the local speed of light is less than it is in a vacuum and less than the speed of the particle?
    Also isn’t the amount of Cerenkov radiation “glow” proportional to the amount of radioactivity in spent fuel? Before spent fuel is removed from the water in a spent fuel pool is the characteristic blue glow essentially gone?

  7. My answers are based on the most recent wind contracts I have seen:
    1) About 300MW of wind turbine nameplate capacity installed and interconnected for $730 million.
    2) Depending on location, 300MW of nameplate should generate around 1,000,000 MWhrs annually. [ A disproportionate amount of it at night and in the winter, at least where I live]

  8. for $730M: approx. cost of 112 turbine Ocotillo Express wind farm, not including the $115M Sect 1603 grant-in-lieu-of-PTC. (published amounts vary from $300M by Pttern Energy to $1B per law360.com). Also not included: cost of the Sunrise Powerlink to get power from Ocotillo over the mountains to SDG&E.
    Amount of power: In the case of Ocotillo Express: 17% c.f. of 265 MW (rated)

    Power generation from wind is fickle and unreliable. Go to BPA’s wind power site and analyze the data. Approx. 30% c.f. with a Std Deviation greater than the average. Plot the data and it looks like a seismograph pen trace.

  9. The last time the INL was called the NRTS was in the 1970s when the USGS updated their maps for the Arco desert in Idaho.

  10. For $730 million the NRC could probably complete the design review and COL for the nation’s first commercial SMR and have change left over 🙂

  11. Ditto the above answers!
    Here is an update on what is happening at that site:

    USA’s Experimental Breeder Reactor-II now permanently entombed https://shar.es/1qDhhD

    CH2M-WG, Idaho, LLC (CWI) said yesterday that crews with the Decontamination and Decommissioning (D&D) Program recently completed pouring more than 3400 cubic yards of concrete grout into the basement of the Experimental Breeder Reactor-II (EBR-II) building to fill in any remaining void spaces and effectively entomb the reactor.
    Workers also removed and treated the last of the sodium coolant from the reactor’s nine heat exchangers. The exchangers were used to cool the liquid metal and direct the steam to a generating turbine to produce electricity when the reactor was operating.

    The three-year, $730 million project, funded through the DOE’s Office of Environmental Management, focuses on early risk reduction and protection of the Snake River Plain Aquifer.

    2 Part Question:
    How many wind turbines could be purchased and installed for $730 million?
    What would the amount of power they would produce annually?

  12. NRTS is in Idaho Falls, Idaho. I guess that the Cherenkov radiation probably named by Fermi. By the way, my grandfather and great uncle were engineers at the Norwegian plant that made the heavy water smuggled out of Norway before the German invasion. The heavy water went to Fermi, Rutherford and others for their fission experiments. So, you could say that I have had a nuclear family prior to the first nuclear plant was built. My sister was with the NRC for >25 years and I have been at a nuclear plant since 1983,

  13. It’s a picture of the Advanced Test Reactor (ATR) at the Idaho National Laboratory, located east of Arco, Idaho.

    The characteristic blue glow of an underwater nuclear reactor is due to Cherenkov radiation. It is named after Soviet scientist Pavel Alekseyevich Cherenkov, the 1958 Nobel Prize winner who was the first to detect it experimentally.

  14. ATR is at the Idaho National Laboratory. Cerenkov radiation is named for Pavel Alekseyevich Cerenkov.

    Christopher Charles
    Editor, Nuclear Energy Overview
    Senior Writer, Communication Services

    Nuclear Energy Institute
    1201 F St NW, Suite 1100
    Washington, D.C. 20004

    T: 202.739.8152
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    E: cic@nei.org
    T: @NEI

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