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
United States Nuclear Regulatory Commission Official Hearing Exhibit Entergy Nuclear Operations, Inc.
In the Matter of:
(Indian Point Nuclear Generating Units 2 and 3) c:..\,.~""R REGlI~;. ASLBP #: 07-858-03-LR-BD01
- l~'~...
Docket #: 05000247 l 05000286 Exhibit #: NRC000053-00-BD01 Identified: 10/15/2012
- 0 Admitted: 10/15/2012 Withdrawn:
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0.... Rejected: Stricken:
- il Other:
NRC000053 Submitted: March 30, 2012 The Basics Who discovered plutonium?
Pluto nium was identified by nuclear chemist Glenn T. Seaborg an d his colleag ues Joseph W. Kennedy, Edwin M. McMilla n, and Arthu r 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?
Pluto nium is created from uranium in nuclear reactors. When uranium-23 8 abso rb s a neut ron, it becomes uranium-239 which ultimat ely decays to plutonium-239.
Different isot opes of uranium and different comb inations of neutron absorptions and radioactive decay, create different isotopes of plut onium.
Some of the plutoni um-2 39 in the fuel rods burn s (fissions) alo ng with uranium and helps produce heat, which is converted into electricity. As fissio n continues, the reactio n prod ucts remai n in t he fuel pellet s and absorb neutrons, slo wing (" poisoning ") the fission process . Fina lly, t he ratio of poisons t o fissio nal mat erials reaches a point at which t he fuel is said to be "spent" and must be replaced . How ever, even spent fuel co ntains some plut onium.
Th e majority of plutonium was produced for nuclear weapons in several government reactors designe d to maximize the prod uction of plutonium. Bet ween 1944 and 1988, t he U.S. built and operated t hese 'pro duction reactors ' at high-security government facilities. In all, th e U.S. produced about 100 met ric t ons of plutonium.
Th e reactors made plut onium by bombardi ng special fuel rods cont aining uranium with ne utro ns. Once t he maximum amount of plutonium was produced, workers removed the fuel rods (now call ed 'spent fuel') from th e reactor. Th e spent fuel rods were extremely radio active, and t he process for recovering t he plutonium used only remot e-cont rolled eq uipment .
First workers used st rong acid to dissolve t he fuel rods. Th en they treated the mixture with chemicals t o precipit ate the plut onium so that it woul d 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 gall ons of exceedingly hazardous mixed wast es of acids and radioactive fission products . Part of our legacy of nuclear weapons production is dealing with t hese high-level wastes .
In extremely rare cases , rocks wit h a high localized concentration of uranium can provide the right conditions for making sma ll amo unt s of plutoni um natura lly. This natural process is called spontaneous fission. Only very small (trace) amount s of nat ural plut onium have ever been found in nat ure.
iTOp of pag e What are the properties of plutonium?
Pluto nium is a silvery-grey metal that becomes yello wish when exposed to air. It is solid under normal conditions, and is chemically reactive.
Pluto nium has at least 15 different isotopes, all of which are ra dioactive. 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, beca use of it s radioactivity.
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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 . Ho wever 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 . stodqJ iles .
Ex posure to Plutonium How does plutonium get into the environment?
Plutonium was dispersed world wide from atmosphenc testin(l 01 nuclear we apons conducted durin(l the 1950s and *60 s. The lallout lrom these tests left very low concentrations 01 plutonium in so ils 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 slo wty s ince the ha~ - liv es 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 we apons testin(l is dispersed widety in the environment. As a resuit, virtualty eve ryone comes irlto contact with extremety small amounts 01 plutonium.
People who live near nuclear we apons production or testin(l sites may have iroc.-eased exposure to plutonium, primarity throu(lh particles in the a ir, 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(l ested with lood or water. Most people have extreme ty low irl(l estion 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 ve ry little heaith risk.
What does plutonium do on ce it gets into the body?
The stomach does rlOt absorb plutonium ve ry well, and most plutonium s wallo wed with lood or water passes from the body throu(lh the leces . When irlhaled, plutonium can remain irl the lun(l s dependin(l upon its particle size and how well the particular chemicallorm disso lves . The chemicallorms that dissolve less eas ity may lod(l e irl the lun(l s or move out with phle(lm, and either be s wallo wed or spit out. But, the lun(l s may absorb chemicallorms that dissolve more eas ity 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 ve ry little heaith risk, s ince 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.-eas in(l the risk 01 cancer. Plutonium is also a to xic 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