ML20237K115

From kanterella
Jump to navigation Jump to search

Forwards List of Several Considerations Re Containment Venting Analysis That Should Be Considered When Conducting Review of Improvements Re Containment Safety Initiative
ML20237K115
Person / Time
Site: Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date: 08/24/1987
From: Varga S
Office of Nuclear Reactor Regulation
To: Capstick R
VERMONT YANKEE NUCLEAR POWER CORP.
References
TAC-62753, NUDOCS 8708270057
Download: ML20237K115 (3)


Text

I August 24, 1987 Docket No.:

50 271

)

Mr. R. W. Capstick Licensing Engineer Vermont Yankee Nuclear Power Corporation 1617 W:wcester Road Framingham, Massachusetts 01701

Dear Mr. Capstick:

~

SUBJECT:

VERMONT YANKEE CONTAINMENT SAFETY INITIATIVE (TAC N0. 62753)

On June 25, 1987, Vermont Yankee Nuclear Power Corporation (VYNPC) submitted a status update and design description for the Vermont Yankee Containment Safety Initiative. We are studying with interest your plans to proceed with improvements related to containment spray, and look fomard to receiving more l

infonnation about your containment venting plans.

Because we consider there are several unanswered questions concerning the containment venting issue, welppreciate your thoughtful deliberate approach.

We note that you intend a thorough rereview of containment vent design and implementation issues, and that you will notify us of the results of your l

review by March 1,1988. We have enclosed a list of several considerations related to containment venting analysis that we would like you to consider in conducting your review.

1 l

Should you have any questions re Manager, V. Rooney (301-492 8344garding this please contact the NRR Project i.

Sincerely,

/s/

Steven A. Varga, Director Division of Reactor Projects I/II Office of Nuclear Reactor Regulation As stated cc:

See next page DISTRIBUTION: lDo'cket' File, local PDR, NRC PDR, SVarga, VNerses, VRooney, BBoge, TMurley,' MRushbrook, PDI-3 R/F, 0GC.Bethesda, EJordan, JPartlow, ACM ( 0), MThadani

  • See previous concurrences 1)FC :PDI-3*
PDI.3
ACIDIR/PDI 3: AD/DRP*
D/DRP

......:...~....___:.._________

NAME :VRooney:lm :MRushbrook :VNerses*

BBoger

.a DATE:08/8/87

05/ /87
08/ /87
08/ /87

. 8 0 /87 0FFICIAL RECORD COPY 8708270057 G70824 PDR ADOCK 05000271 p

PDR U

l

'i 1

Docket No.: 50-271

)

Mr ' R..W. Capstick i

'Lic sing Engineer Vermo t Yankee Nuclear Power Corporation 1617 W cester Road Framingh

, Massachusetts 01701

Dear Mr. Ca tick:

SUBJECT:

VERM iT YANKEE CONTAINMENT SAFETY INITIATIVE (TAC NO. 62753)

On June 25, 1987, ermont Yankee Nuclear Power Corporation (VYNPCI submitted a status update and sign description for the Vemont Yankee-Containment Safety Initiative. We are tudying with interest your plans to proceed with improvements related containment spray, and look forward to receiving more information about your ntainment venting plans.

Because we consider the co tainment venting issue to be fraught with conflicting safety objectiv

+nd-to be more complex than the containment spray issue, we appreciate yo r thoughtful deliberate approach, We' note that you intend a thorough rereview f containment vent design and implementation issues, and that you will notify us of the results of your review by March 1, 1988. We have enclosed a list of everal considerations related to containment venting analysis which may be of us to you in conducting your review.

.Should you have any questions regardi this please contact the NRR Project Manager, V. Rooney (301-492-8344).

Sin rely, j

Steven A.

rga, Director Division of eactor Projects I/IT Office of Nuc ar Reactor Regulation cc: See next page DISTRIBUTION: _ Docket File, Local PDR, NRC PDR, SVarga, VNerses, Vkooney, BBoger, MRushbrook, PDI-3 R/F, GC.Bethesda. EJordan, JPartlow, ACRS (10) rq A/

(

OFC :PDI.3( /

i-3

ACTDIR/PDI.3:A
D/DRP NAME :VRoo/t %.:......

ney:Im :MRus ok :VNerses oger

SVa rga DATE :08//)S/87
08 187
08/A0/87
08,/LP /87
08/ /87 OFF.ICIAL RECORD COPY

't Enclosure CONTAINMENT VENTING CONSIDERATIONS A thorough review of considerations involved in containment venting would

. include:

1)

A comprehensive analysis of accident sequences, with their estimated frequency.of occurrence, for which the vent would be called upon to operate.

2)

An estimate of the fraction of those sequences where the vent would be operated but where the accident would have been terminated short of containment failure without vent operation:

(a) electric power returned to service (b) equipment returned to service (c) mis-diagnosed situation corrected by operators 3)

A comprehensive analysis of sequences that (a) could be improved by correct use of the vent, or (b) could be initiated or made worse by incorrect operation of the vent 4)

An analysis of sequences that could lead to containment failure by operation of the vent followed by excessive pressure differential (buckling).

5)

Analysis of the probability of vent failure when called upon.

6)

Analysis of maintenance or surveillance errors on the vent system that could induce accidents.

7)

An estimate of the radioactivity released for all sequences when the vent could be opened, including both correct usage according to procedures and incorrect usage due to human error or equipment malfunction.

l l

l

_. _ _.. -. -. _ _ - - - - _ _