ML19208B980
| ML19208B980 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/01/1979 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19208B981 | List: |
| References | |
| NUDOCS 7909240252 | |
| Download: ML19208B980 (2) | |
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i Kralltown Elementary School
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Fifth Grade Class -
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R.D. #1 WeI-t East Berlin, PA.1731,6
Dear Fifth Grade Class:
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Your letters to the President and Dr. Hendrie~ have been referred.to me for reply. We at the Nuclear Regulatory Connission (NRC) appreciate your i
concern over the ihree Mile Island accident and we trust our answers to i
your questions will,. help you to better underscand nuclear power plants.
I
. Question: How-long will it take to bring. reactor Urif t No. 2 to a cold shutdown?
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Answer:
The reactor reached cold shutdown on April 27, 1979.
The~ phrase " cold shutdown" has a special definition
.at.NRC.
It means the reactor-is subcritical (the chain reaction is stopped); and the reactor coolant water temperature is less than 200*F (during normal-I' operationthistemperatureisabout560*F). We would point out that the reactor has been subcritical since the first moments.of the accident. However,-
2 after the reactor is made subcritical the fuel r-continues to generate heat from the radioactive decay of fission products. Nomally a reactor can go from full power to cold shutdown in about 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, but the damage to the reactor fuel and.Other circumstancer requires that the cool down of the Unit 2 reactor be l
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Question: ~Why was Three Mile Island built so close to a' heavily j
populated area?
s Answer:
Normally to s' ave the cost. of building large trans-mission lines, power companies will build power s
plants close to where the electricity will be used, and that's usually where the people are. The NRC's regulations limit how close a power plant can be to a city based on (1) the design of the reactor, t
(2) the ' ease of evacuating the people irmediately j
around the reactor, and (3) the average population k
density around the reactor. The TMI reactors meet l
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.n Question: Will the nuclear neutrali7fng chemicals be' safe 7' Answer:
' Atoms can be made radi6a,ctive by bombardment with d
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> > nuclear ~ particles, like for instance neu'trons.
s Once an atom is made radioactive, the radioactivity
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will decay away exponentially. However, there are
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no chemicals.which can neutralize, radioactive atoms.
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Radiyactive~ atoms or materials shoulf not' be. cone 9
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3 fused with things " contaminated" with radioactive atoms. For instance a floor can become contamtnated by spilling a radioactive chemical on the floor..In I
t.his. case, one might be abib to scrub the radioactive chemical off the-floor and put it in a wash bucket.
The radioactivity does not disappear, it.jusc gets
-moved from one ~ place to another.
Sincerely, Original signed by H.R.Denton Harold R. Denton, Director Office of Nuclear Reactor Regulation
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s DISTRIBUTION Docket File 50- 5 M NRC P",.!
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