ML20044A213

Requests Info Re Installation of Direct Torus Vent Sys at Pilgrim

ML20044A213
Person / Time
Site:	Pilgrim
Issue date:	04/24/1990
From:	Griffin W PLYMOUTH, MA
To:	Carr K NRC COMMISSION (OCM)
Shared Package
ML20044A212	List: ML20044A213
References
NUDOCS 9006280216
Download: ML20044A213 (3)

Text

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. .. . 1 TOWN OF PLYMOUTH ,

,jg j OFF1CE OF SELECTMEN ,

( .' THE SELECTMEN 11 IJncoln Street

"=in== Ens GEoncEw. CAMERON Plymouth. Massachusetts 02360 D^{D

, c ^Nr o s$' chainnan wn.uAM n crumN ExinrnvE strRETARY FAX (508) 747-3064  ;

(508)747 1620 April 24, 1990 1

Mr. Kenneth M. Carr, Chairman Nuclear Regulatory Commission Washington, DC 20555

Dear Chairman Carr:

I am writing on behalf of the Board of Selectmen and Nuclear Matters Committee of the Town of Plymouth to address several ,

questions to the Commission relative to the direct torus vent now operational at the Pilgrim Huclear Power Station.

It is the understanding of both the Board of Selectmen and Nuclear Matters Committee that the direct torus vent system at Pilgrim 1s the first such installation in the world and is being used as a test case for twenty-four other reactors in the United States.

These factors and many other concerns require the town to address the following questions and requests to the Nuclear ,

Regulatory Commission:

1. What are the decontamination factors for the pool for various isotopes? In other words, how well does the wet well pool scrub out the fission byproducts, keeping the radioactive particles from releasing to atmosphere? '

l- 2. Please provide a graph of offsite radiation doses based on the possibility of a vacuum breaker valve remaining <

open at 10%, 25X, 50% and 100X.

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! 3. The NRC has recommended venting at the containment i design pressure as_a minimum, or in the case of Pilgrim, at 60 pai. Why is the Pilgrim DTVS rupture disk set at half that, at 30 psi?

4. What is the minimum containment pressure allowed by procedures at which the operators could open the DTVS outboard containment valve, AO-5025?

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l LETTER TO NUCLEAR REGULATORY COMMISSION ISSUES RELATING TO DTVS APRIL 24, 1990 PAGE 2 l

5. Please provide information on the reliability of the hydrogen and oxygen concentration monitors at Pilgrim.

What percentage of the time have both systems been accurately functioning? I

6. Does the NRC concur that the use of the DTVS does not involve an unreviewed safety quest /.on?

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7. Does the NRC concur that the use of the DTVS does not '

require changes to P11 grim'a technicul specifications?

8. Does the NRC judge the DTVS to improve the safety at Pilgrim?

9. bove the NRC conclude that tb 'netallation and use of the DTVS are acceptable under .he provisions of le CFR 59.59?

10. Does the NRC conclude that Boston Edison has adequately considered the technical issues germane to the DTVS?

11. Why was the automatic reclosure on high radiation of  !

j valve AO-5025 deleted during the design revision of the system? )

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12. Generic letter 89-16 indicates some benefits of a hardened wet well vent to reduce core damage frequencies during SBO and ATWS accident scenarios. Is this true for Pilgrim?

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LETTER TO NUCLEAR REGULATORY COMMISSION ISSUES RELATING TO DTVS APRIL 24, 1990 <

'PAGE 3 dQ[&

The Board of Selectmen and'Huclear Mattera Committee appreciate your immediate attention to these important issues. By copy cf this letter, I am informing the Boston {

Edison Company of this inquiry and inviting them to submit l any relevant information to the town that addresses the concerns raised.

Your time and consideration is appreciated.

Very truly ours,

[ rt'kW -

William R. Griff J

' Executive Secretary i

c. c. Boston Edison Company  ;

Nuclear Matters Committee i Doug Hadfield, Civil Defense Director j l

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