ML20204H072

Responds to Re Facility & Nuclear Power Plant Entombment Following Accidents Involving Core Melt. Evaluation of Severe Accident Risk for Us Reactors Indicates Likelihood of Needing Entombment Very Remote

ML20204H072
Person / Time
Site:	Seabrook
Issue date:	03/19/1987
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	Weddle M HOUSE OF REP.
Shared Package
ML20204H077	List: ML20204H072 ML20204H144 ML20204H211
References
NUDOCS 8703260540
Download: ML20204H072 (4)

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MAR 191987 Distribution vCsntral File PDR DSR0 Chron TSpeis TMurley BSneron The Honorable Michael Weddle JTaylor RSilver New Hampshire House of Representatives WKerr PPAS Concord, New Hampshire 03301 JMurray TNovak EBeckjord DMossburg EDO Rdg. (002590) JSniezek

Dear Mr. Weddle:

HDenton Your letter of February 17, 1987 to Chairman Zech, regarding the_Seabrnok plant has been referred to me for response. Your letter expressed reservations as to whether nuclear power plants, and in particular the Seabrook -

plant, could be entombed following an accident involving core melt. In a <

letter dated February 3,1987 to the Office of Legislative Services, State of New Hampshire, I stated that should entombment be needed, we see no impediment -

to providing protection similar to that provided at Chernobyl. I would like to elaborate on that response.

The NRC does not require studies to be performed to determine if and how [

entombment should be done at each nuclear reactor following a core melt L.

accident. Our evaluation of severe accident risk for U.S. reactors indicates that the likelihood of needing entombment is very remote. The U.S reactors incorporate stringent design and operation requirements to prevent a severe meltdown accident and provide containments to help mitigate the consequences of such an accident in the unlikely event one was to occur. The study of the implications of the Chernobyl accident for U.S. reactors, which will be sent to you when it is available, supports the position that U.S. reactors are funda-mentally different than the Chernobyl reactor and are not subject to the same accident. This the fact that the (TMI-2) position is though accident, supported by the severe, didexperience at the not result in TMI-2 an('for need entombment. We note, however, that the Soviets were able to devise a success-ful ad hoc plan for entombment subsequent to the ac^icent. The design of an entombment scheme can best be done after the details of the accident are known, and we believe there is sufficient capability within the United States to successfully design and implement an entombment scheme in the unlikely event that such an action were necessary.

Your letter also asks whether there are sufficient protective radiation suits to sustain vital operations at nearby military facilities should a massive release of radioactivity occur. We are not aware of the specific provisions by the military to sustain vital operations in the unlikely event of a large G703260540 DR 870319 ADOCK 05000443 PDR

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9 The Honorable Michael Weddle -2_

radioactive release at Seabrook. However, in the event of any such release,

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the NRC, as well as other Federal Agencies, would provide appropriate support to the military to minimize the impact on vital military operations.

Sincerely, C.bbal S';aed by

, p.n.03atcq Harold R. Denton, Director Office of Nuclear Reactor Regulation i

• See previous sheet for concurrences

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Distribution Central File RVollmer DSRO Chron TSpeis TMurley BSheron the Honorable Michael Weddle JTaylor RSilver

. State of New Hampshire, House of WKerr PPAS sHepresentatives JMurray TNovak Concord, New Hampshire 03301 EBeckjord DMoss rg EDO Rdg. (002590)

Dear Mr. Weddle:

HDenton Your letter of February 17, 1987 to Chairman Zech, regarding the eabrook plant has been' referred to me for response. Your letter expre ed reservations as to whether nuclear power plants, and in parti lar the Seabrook plant, could be entombed following an accident involving coy melt. In a letter dated February (3,1987 to the Office of Legislative / Services, State of New Hampshire, I stated that should entombnent be needed/ we see no impediment to providing protection similar to that provided at Ch rnobyl. I would like to elaborate on that response._

N Our evaluation of severe accidenbrisk and the imp ications of the Chernobyl event for U.S. reactors indicate that the likelihood of needing entombment is very remote. The U.S reactors differs significalitly from Chernobyl in that they incorporate stringent design and operatjd'n requirements to prevent a severe meltdown accident and provide stronger containments to help mitigate the consequences of such an accident in the unl We also note that the Soviets were able to tfevikely ise aevent one was successful to occur.

ad hoc plan for entombmentsubsequenttotheaccident/Thedesignofanentombmentschemecan best be done after the details of the' accident are known, and we would expect that there would be sufficient capability within the United States te success-tully design and implement an ent6mbment scheme in the '

unlikely event that such an action were necessary.

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Your letter also expresses c$ncern about continuation of'v. ital operations at nearby military facilitiefshould a massive release of radioactivity occur.

Again, we would expect that the experts and resources needed'to implement necessary actions could be rapidly crganized to acceptably minimize disruption of vital operations./ N

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Sincerely, N

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,- Harold R. Denton, Director Office of Nuclear Reactor Regulation

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' . '}~g OY EDO PRINCIPAL CORRFSPONDENCF CONTROL FROM: Di lF : 03/19/87 EDO CONTROL: 002590 nOC DT: 02/17/87 MICHAEL WEDDLE FINAL RFPLY:

NEW HAMPSHIRE STATE REPRESENTATIVE TO:

CHAIRMAN ZECH FOR SIGNATURE OF: ** GRFEN ** SFCY NO:

DENTON DESC: Rni tT I NG:

CONCERNS RE SEABROOK Mt.lRLEY TAYLOR DATE: 03/05/87 MlJRRAY ASSIGNED TO: NRR CONTACT: ItFNTON KERR.SP BECKlORD SPECIAL INSTRIJCTIONS OR REMARKS:

-PEF. EDO 2436.

NRR RECEIVED: 03/05/87 ACTION:  %

D500 - Spfu.y NRR ROUTING: DENTON/VOLLMER l PPAS MOSSBURG

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