ML20108D311

Forwards Marked Up Proposed Changes to ABWR Design Description Resulting from Info Developed in Course of ABWR First-Of-A-Kind Engineering Program

ML20108D311
Person / Time
Site:	05200001
Issue date:	04/03/1996
From:	Quirk J GENERAL ELECTRIC CO.
To:	Crutchfield D NRC (Affiliation Not Assigned)
References
NUDOCS 9605080030
Download: ML20108D311 (5)

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GENuclearEnergy Joseph F Oud GeneralDectric Company ABhR Licensing Manager 115 Catner Avenue ML 782; San Jose CA 951251014 f+0jectManager ABARCertitcaton 408 925-6219(phone) 408 925-4257(facsimile)

Apiil 3,1996 Docket No.52-001 Mr. Dennis M. Crutchfield Associate Director for Advanced Reactors g  !

and License Renewal V y//

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 j 1

Dear Mr. Crutchfield:

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Transmitted herewith,in the form of markups to pages of the AllWR Design Control l I

Document (DCD), are ten proposed changes to the AllWR design description which result from information developed in the course of the AllWR First-Of-A Kind Engineering l (FOAKE) program. The need for the proposed changes prior to completion of rulemaking has only recently been determined from an updated analysis of FOAKE detailed design information. Ten copics are enclosed for resiew by the NRC staff. The background for that analysis and this submittal is set forth below.

CE undertook the AllWR FOAKE activity pursuant to ajune 1993 contract with the Advanced Reactor Corporation (ARC) to perform detailed design of the AllWR forits use in the United States. The basic approach of the CE FOAKE actisityis to develop the design details of the AllWR consistent with the requirements of the design undergoing NRC certification, a key objective being the development and maintenance of a highly standardized design. This means that the cer Tied design and the FOAKE design must be consistent, with the FOAKE design being much more detailed in its description.

The FOAKE design activity may identify changes which wouki result in a substantial benefit to safety, reliability or economy. Their considemtion, however, is done under an l approach which is closely controlled. Any proposed design change to the DCD is processed in accordance with rigorous internal GE review procedures; and proposed changes are only accepted for compelling reasons, in the spirit of maintaining the detailed AllWR design as close as practicable within the boundaries of the DCD. In December of 1995, two design changes were identified that were needed to bring the L)CD into compliance with NRC l regulations in effect at the time of FDA issuance. In order to take full advantage of the thoroughness of the FOAKE activity,it was then decided to re-evaluate all the FOAKE i

L Engineering Change Authorizations (ECAs) for purposer of determining if any other

@@@ proposed DCD changes should accompany the two that were initially identified. Enclosed is l g a summary description of the resulting proposed DCD changes and of the screening criteria

! on used by GE to evaluate whether the FOAKE information requires, or otherwise merits, change to Tier 1 orTier 2 of the DCD.

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@@ Five of the changes proposed herewith are to Tier 1 (and corresponding portions of Tier 2) of the DCD and five are to Tier 2 only. None of the proposed changes are necessary n

to assure adequate protection of the public health and safety. ttr CRather, as de 0 ~8 8 10 1

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enclosure, two are proposed to bring Tier 1 or Tier 2 into compliance with regulations in effect at the time the ABWR FDA was issued, one is proposed to effect a change to technical specincations, four are proposed to make the design described in the DCD functionally operable as intended, and three would efTect design improvements which require minor modiGcations to Tier 1 and which GE thus believes should be incorporated in the DCD at this time.

The FOAKE program has identiGed a number of additional desimble design improvements; however, the implementing design changes need not be made at this time l

since they qualify for post-certincation S50.59-type change treatraent (i.e., they do not affect Tier 1 or Tier 2* or technical specifications, or result in an unreviewed safety question). Those changes will be made in accordance with governing procedures as established by the Commission.

We will, of course, cooperate fully with the staffin completing early review and action of the proposed design changes submitted herewith.

Sincerely yours, Joseph F. Quirk cc: (w/0 attachments)

SA Ilucik (GE)

Wf Russell (NRC)

FJ 51iraglia (NRC)

TH Boyce (NRC)

Shi Franks (DOE)

FA Ross (DOE)

ND Fletcher (DOE)

A hlachiels (EPRI) l l

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l ABWR Design Change Assessrnent Review of FOAKE Design Changes Change Description Tier 1 Screen Remarks No. Impact (Notes) 1 Change the Reactor Building and Radwaste Yes 4 This change addresses a lluilding HVAC Systems to use electric heating in reliability & maintainability place of hot water heating, split the single intake issue, rather than a safety configuradon into three to provide redundancy, concern. The change results and use high c!Ticiency filters in place of medium in a minor modiGcation to

grade bag-type filters. Use of elecuic heating will Tier 1, although there is no avoid in-scivice freezing. The change will funcdonal Tier 1 impact.

provide air intake redundancy to satisfy system maintenance needs.

l 2 Add an additional chil er/ pump set to the No 4 The change does not impact

Emergency Chilled Water System. This provides Tier 1 because Tier 1 does functional redundancy to avoid the loss of not specify divisional l cooling for the Control and Reactor lluilding equipment quantity and l clectrical rooms, potentially challenging logic.

l c!ccu ical equipment environmental qualiGcation l temperature limits. The added redundancy will l also satisfy system maintenance needs.

! 3 Add one smoke removal fan in the bypass duct Yes 3 The change ensures l around exhaust fans in cach of the three funcdonality and compliance

! divisions of the Reactor lluilding electrical with Tier 2 commitments.

! equipment room ilVAC. Additionally, for the Control Iluilding IIVAC, use two speed fims of adequate capacity in place of existing single speed fans to provide acceptable smoke removal capability for the habitability and .=afety-related equipment areas. These changes are necessary to comply with the accepted smoke removal

, method prescribed by the ASilRAE and NFPA standards referenced in die Tier 2.

4 Reassign the Main Control Room exhaust fans Yes 4 The change has no safety "II" as exhaust fans "C," and exhaust fans "C" as significance and no impact on exhaust fans "II." This nomenclature change will the safety functions described e avoid a potential divisional cross-over of cooling in Tier 1. However,it does and power. impact designations on Tier 1 and Tier 2 figurcs.

5 This change package identifies various Tier 1 and Yes 3 Tier I and Tier 2 figures and Tier 2 inconsistencies, such as the radiadon zone text are modified.

classific:uion of a room shown in the Reactor i fluilding radiation zone maps, Elevation 12300.

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l ABWR Design Change Assessment Review of FOAKE Design Changes .

Change Description Tier 1 Screen Remarks l No. Impact (Notes) 6 Provide power for each pair of motor operated Yes 1 The change is necessary l isolation dampers in series for the Control Room to ensure compliance IIabitability Area IIVAC System from independent with single failure l Class IE division power supplies,instead of criteria.

powering bodi dampers from the same source.

This will ensure that at least one of two normal inlet or exhaust air isolation dampers in series will  ;

close and prevent leakage. Also, the Tier 1 figure I is modified to reficcia cross tie on the outside air inlet ducts of the Emergency Filtration Unit. This  ;

j cross-tie is curreatly shown in Tier 2 but was not  !

been reflected in the Tier 1 figure, j l 7 Delete the rupture disks originally intended to No 3 The change is necessary -

protect the low pressure exhaust side of the RCIC for conformance to turbine case and exhaust line from Tier 2 commiunents on

! overpressurizadon. Existence of the rupture disks ISLOCA.

l is not consistent widi interfacing system L.OCA l (ISLOCA) requirements. Removal of the rupture disks and upgrading of the associated piping and valves corrects a SSAR inconsistency regarding l ISLOCA.

j S Upgrade the FMCRD and scram piping design No 1 A change in design l pressures I ased on evaluations of water hammer pressure is needed due to l cfTects. The changes are consistentwidi the ASME new design information.

Code which requires use of equipment events The change ensures rather than plant events in determining the design compliance with ASME pressure. Code per 10CFR50.55a.

9 Use a higher strength material for the lower No 3 Ilased on detailed design drywell (L/D) access tunnel and RPV pedestal, evaluations, the materials based on the results of detailed design evaluations. specified in the DCD are Structural analyses for the L/D access tunnel not adequate.

indicate high thermal stresses which exceed the allowahics; these detailed structural evaluations l were not performed during the SSAR review stage of the licensing process.

! 10 Correcdon ofinconsistencies to technical No 2 Ilased on detailed design specifications (Chapter 16 and related Tier 2 evaluation and review of sections) desired for certification. technical specifications.

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Screening Criterim CE will not propose to change its DCD during the period from FDA issuance to Design Certification unless:

1.) The change corrects an error or deficiency necessary to assure adequate protection to the public health and safety, or to bring the DCD (Tier 1 or Tier 2) into compliance widi regulations in efTect at the time die AllWR FDA was issued; 2.) The change affects a technical specificadon; 3.) The change is necessary to make die DCD design functionally operable (as intended); or 4.) The change is a design improvement which GE determines shonld be incorpomted into the design at this time.

All changes which sadsfy Criteria 1, ? or 3 shall be incorporated into die DCD prior to Design Certificadon. Any Tier 1 or Tier 2 changes which sansfy Criterion 4 should be addressed on a case-by-case basis.

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