ML12339A488
| ML12339A488 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 03/30/2012 |
| From: | Environmental Protection Agency |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| References | |
| RAS 22152, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML12339A488 (3) | |
Text
NRC000053 Submitted: March 30, 2012 United States Nuclear Regulatory Commission Official Hearing Exhibit In the Matter of:
Entergy Nuclear Operations, Inc.
(Indian Point Nuclear Generating Units 2 and 3)
ASLBP #: 07-858-03-LR-BD01 Docket #: 05000247 l 05000286 Exhibit #:
Identified:
Admitted:
Withdrawn:
Rejected:
Stricken:
Other:
NRC000053-00-BD01 10/15/2012 10/15/2012 c:..\\,.~""R REGlI~;.
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- il The Basics Who discovered plutonium?
Plutonium was identified by nuclear chemist Glenn T. Seaborg and his colleagues Joseph W. Kennedy, Edwin M. McMillan, and Arthur C. Wahl, in 1941 at the University of California - Berkeley. However, wartime secrecy prevented them from announcing the discovery until 1948.
iTop of page Where does plutonium come from?
Plutonium is created from uranium in nuclear reactors. When uranium-238 absorbs a neutron, it becomes uranium-239 which ultimately decays to plutonium-239.
Different isotopes of uranium and different combinations of neutron absorptions and radioactive decay, create different isotopes of plutonium.
Some of the plutonium-239 in the fuel rods burns (fissions) along with uranium and helps produce heat, which is converted into electricity. As fission continues, the reaction products remain in the fuel pellets and absorb neutrons, slowing ("poisoning") the fission process. Finally, the ratio of poisons to fissional materials reaches a point at which the fuel is said to be "spent" and must be replaced. However, even spent fuel contains some plutonium.
The majority of plutonium was produced for nuclear weapons in several government reactors designed to maximize the production of plutonium. Bet ween 1944 and 1988, the U.S. built and operated these 'production reactors' at high-security government facilities. In all, the U.S. produced about 100 metric tons of plutonium.
The reactors made plutonium by bombarding special fuel rods containing uranium with neutrons. Once the maximum amount of plutonium was produced, workers removed the fuel rods (now called 'spent fuel') from the reactor. The spent fuel rods were extremely radioactive, and the process for recovering the plutonium used only remote-controlled equipment.
First workers used strong acid to dissolve the fuel rods. Then they treated the mixture with chemicals to precipitate the plutonium so that it would settle out. The process was very expensive and at the time made plutonium about the most expensive material on earth. This processing also left behind over 100 million gallons of exceedingly hazardous mixed wastes of acids and radioactive fission products. Part of our legacy of nuclear weapons production is dealing with these high-level wastes.
In extremely rare cases, rocks with a high localized concentration of uranium can provide the right conditions for making small amounts of plutonium naturally. This natural process is called spontaneous fission. Only very small (trace) amounts of natural plutonium have ever been found in nature.
iTOp of page What are the properties of plutonium?
Plutonium is a silvery-grey metal that becomes yellowish when exposed to air. It is solid under normal conditions, and is chemically reactive.
Plutonium has at least 15 different isotopes, all of which are radioactive. The most common ones are Pu-238, Pu*239, and Pu-240. Pu-238 has a half-fife of 87.7 years. Plutonium-239 has a half-life of 24,100, and Pu-240 has a half-life 6,560 years. The isotope Pu-238 gives off useable heat, because of its radioactivity.
'9'Top of page
What is plutonium used for?
Plutonium-239 is used to make nuclear weapons. For example, the bomb dropped on Na(lasaki, Japan, in 1945, contained PU-239. The plutonium irl the bomb under(loes ~
in an arran(lement that assures enormous ener(lY (leneration and destructive potential.
The isotope, plutonium-238, is rlOt uselullor nuclear weapons. However it (lenerates si(lnifocant heat throu(lh its decay process, which make it useful as a lon(l-lived power source. Usin(l a thermocouple, a dev;ce that converts heat into electlle power, satellites rety on plutonium as a power source. Tiny amounts also provide power to heart pacemakers.
Some lorei(ln countries mtx isotopes 01 plutonium and uranium to manufacture special reactor luel called mtxed-o><ide luel, lor commercial nuclear power reactors. The plutonium ioc.-eases the power output. The u.s. does not currently manufacture mtxed-oxide ruel, but is lundin(l research irl this type 01 reactor luel as a means 01 dealin(l with excess plutonium irl u.s. stodqJiles.
Exposure to Plutonium How does plutonium get into the environment?
Plutonium was dispersed world wide from atmosphenc testin(l 01 nuclear weapons conducted durin(l the 1950s and *60s. The lallout lrom these tests left very low concentrations 01 plutonium in soils around the world.
Nuclear weapons production and testm(l lacilities (Hanlord, WA; Savannah River, GA; Rocky Flats, CO; and The Nevada Test Site, irl the United States, and Mayak and Semi Plaf,nsk irl the lormer Soviet Union), also released small amounts. Some releases have occurred irl accidents with nuclear weapons, the reentry 01 satellites that used Pu-238, and from the Chemobyl nuclear reactor accident.
How does plutonium change in the environment?
All isotopes 01 plutonium under(lo radioactive decay. As plutonium decays, it releases radiation and lorms other radioactive isotopes. For example, Pu-238 emits an alpha particle and becomes uranium-234; Pu-239 emits an alpha particle and becomes uranium-235.
This process happens slowty since the ha~ - lives 01 plutonium isotopes tend to be relativety Ion(l: Pu-238 has a ha~ -I~e 0187.7 years; Pu-239 has a ha~ -I~e is 24,100 years, and Pu-240 has a ha~ -I~e 01 6,560 years. The decay process continues until a stable, non-radioactive element is lormed.
How do people come in contact with plutonium?
Residual plutonium from atmosphenc nuclear weapons testin(l is dispersed widety in the environment. As a resuit, virtualty everyone comes irlto contact with extremety small amounts 01 plutonium.
People who live near nuclear weapons production or testin(l sites may have iroc.-eased exposure to plutonium, primarity throu(lh particles in the air, but possibty lrom water as well. Plants (lrowin(l irl contaminated soil can absorb small amounts 01 plutonium.
How does plutonium get into the body?
People may irlhale plutonium as a contaminant irl dust. It can also be irl(lested with lood or water. Most people have extremety low irl(lestion and irlhalation 01 plutonium. However, people who live near (lovemment weapons production or testm(l lacilities may have ioc.-eased exposure. Plutonium exposure extemal to the body poses very little heaith risk.
What does plutonium do once it gets into the body?
The stomach does rlOt absorb plutonium very well, and most plutonium swallowed with lood or water passes from the body throu(lh the leces. When irlhaled, plutonium can remain irl the lun(ls dependin(l upon its particle size and how well the particular chemicallorm dissolves. The chemicallorms that dissolve less easity may lod(le irl the lun(ls or move out with phle(lm, and either be swallowed or spit out. But, the lun(ls may absorb chemicallorms that dissolve more easity and pass them into the bloodstream.
Once in the bloodstream, plutonium moves throu(lhout the body and irlto the bones, liver, or other body or(lans. Plutonium that reaches body or(lans (leneralty stays in the body lor decades and continues to expose the surroundin(l tissue to radiation.
Health Effects of Plutonium How can plutonium affect people's health?
Extemal exposure to plutonium poses very little heaith risk, since plutonium isotopes emit alpha radiation, and almost no beta or (lamma radiation. In contrast, intemal exposure to plutonium is an extremety serious heaith hazard. It (leneralty stays irl the body lor decades, exposin(l or(lans and tissues to radiation, and iroc.-easin(l the risk 01 cancer. Plutonium is also a toxic metal, and may cause dama(le to the kidneys.
Is there a medical test to determine exposure to plutonium?
There are tests that can reliabty measure the amount 01 plutonium irl a urine sample, even at very low levels. Usirl(l these measurements, scientists can estimate the total amount 01 plutonium present in the body. other tests can measure plutonium irl soft tissues (such as body or(lans) and irlleces, bones, and milk. However, these tests are not routinety available irl a doctor*s o/foce because they require special laboratory equipment.
http://www.epa.gov/radiation/radionuclides/plutonium.html#affecthealth