ML20207L807

Discusses NRC Response to B&W ATWS Owners Group on Diverse Scram Sys & ATWS Mitigating Sys Actuation Circuitry.Required ATWS Should Be Installed During 9R Refueling Outage as Shown on Integrated Living Schedule

ML20207L807
Person / Time
Site:	Three Mile Island
Issue date:	10/06/1988
From:	Hernan R Office of Nuclear Reactor Regulation
To:	Hukill H GENERAL PUBLIC UTILITIES CORP.
References
TAC-59151, NUDOCS 8810170452
Download: ML20207L807 (3)

Text

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'Cccke't No. 50-289 00I # I'1988 Mr. Henry D. Hukill, Vice President and Director - TMI-1 GPV Nuclear Corporation P. O. Box 480 i Middletown, Pennsylvania 17057 l i

SUBJECT:

NRC RESPONSE TO THE B&W ATWS OWNERS GROUP 1

ONDSSANDAMSAC(TACH 0.59151) l As you are aware, a reeting was held on August 17, 1988 between representatives

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of the B&W Owners Group (BWCG) and the NPC regarding the NRC staff's position on the various issues covered in the staff's generic C&W safety evaluation (SE) i regarding the ATWS issue (10 CFR 50.62). The raain point of disagrecrent was the issue of power supply independence. In this treeting, the staff presented three options on this inatter which it considered acceptable. These three approaches have been forrally decurrented in the letter sent to the Chairn:an of tie BWOG ATKS Ccernittee dated Septerber 7,1908, a copy of which is attached.

In suwary, we stated in cur letter to Mr. Stalter our preference for adoption of the first option. Powever, you tray wish to consider each of the three options

outlined in the enclosed letter in respending within the 90-day response period

requested in cur letter to you dated July 7,1988, transinitting our generic B&L' i J ATUS SE. You should prceptly sutait your plant specific conceptual dcsign for  ;

1 the option ycu have selected. The NRC will review your conceptual design package within 30 days and provide you with an apptuval or disapproval with ccernents.

I Since the generic design review has been certpleted and the optiens acceptable to the staff for resolving the ATUS power supply issue are sufficiently clear, it i

is our position that cur 50fety evaluation of your plant-specific sutoittal does nnt have to precede your irplenentation of the required ATKS equiprent. Accord- -

] irgly, your plant should irstall, upon receipt of our approval of your conceptual

ATKS design, the required ATKS equiprent during the SR refueling cutage as shown '

j en ycur integrated living schedule. If this cannot be acctelished, provide justi-  !

fication in accordance with 10 CFR 50.6P(d), for our review and approval.  !

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g Fr. Fenry D. Hukill If ycu have any questions on this matter, please contact rne at (301) 49P-1320.

Sincerely.

Perald L', Hernan, Senior Project l'anager Project Directorate I-4 Division of Reactor Projects I/I!

Office of fluclear Peactor Regulatien

Enclosure:

As stated cc w/ enclosure:

See rext page DISTRIBilTION D'o'cVeY T W tFC !. Local FCRs PDI-4 Feg.

SVarga, 14/E/4 BCoger, 14/A/0 Stierris RFernen CCC (for info only)

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j . .Mr. Henry D. Hukill Three Mile Island Nuclear Station, i GPU Nuclear Corporation Unit No. 1 l t

1 I i cc: (

G. Broughton Richard Conte

i. 0&M Director, TM1-1 SeniorResidentInspector(THI-1)

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) GPU Nuclear Corporation U.S.N.R.C. i I

Post Office Box 480 Post Office Box 311 i Middletown, Pennsylvania 17057 Middletown, Pennsylvania 17057  !

4 Richard J. McGoey

Manager, PWR Licensing Regional Administrator, Region !  !

GPU Nuclear Corporation U.S. Nuclear Regulatory Comission l 100 Interpace Parkway 475 Allendale Road ,

Persippany, New Jersey 70754 King of Prussia, Pennsylvania 19406  !,

4 C. W. Smyth Robert B. Borsum (

i THI-1 Licensing Manager Babcock & Wilcox j GPU Nuclear Corporation Nuclear Power Generation Division i Post Office Box 480 Suite 525 i l Middletown, Pennsylvania 17057 1700 Rockville Pike Rockville, Maryland 20852 l Ernest L. Blake, Jr., Esq. Governor's Office of State Planning Shaw, Pittman, Potts & Trowbridge and Development 2300 N Street, N.W. ATTN: Coordinator, Pennsylvania Washington, D.C. 20037 State Clearinghouse Post Office Box 1323 Harrisburg, Pennsylvania 17120 7 1 1 Larry Hochendoner Thomas M. Ger"sky, Director l

! Dauphin County Comissioner Bureau of Raciation Protection I j Dauphin County Courthouse Pennsylvania Departe.ent of l i Front and Market Streets Environmental Resources l Harrisburg, Pennsylvania 17120 Post Office Box 2063  !

l Harrisburg, Pennsylvania 17120 l t

David D. Maxwell, Chairean Docketing and Service Section i Board of Supervisors Office of the Secretary  ;

Londonderry Township U.S. Nuclear Regulatory Comissicn  !

RFD#1 - Geyers Church Road .Weshington, D.C. 20555 l Middivtown, Pennsylvania 17057 .

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,' September 7, 1988 Mr. L. C. Stalter Chairr.an BWOG/ATWS Comittee Davis Besse Nuclear Power Station 5501 Norths.R.2(MailStop3205) -

Oak Harbor, Dhto 43449

SUBJECT:

AUGUST 17, 1988 B&W/NRC ATWS MEETING The purpose of this letter is to sumarize r.ajor points addressed during the meeting which was held with the B&W ATWS owners group on August 17, 1988 to discuss the overall ATWS Rule requirenents including power supply independence as related to the staff generic B&W ATWS SER.

Af ter a presentation by you and other merbers of the owners group, the staff provided clarification on various acceptable design options that would resolve the power supply independence issue. We concluded that each licensee should consider each option as it applies at each specific plant. The following options were presented by the staff:

1. provideaDSS/AMSACdesignasdepictedintheviewgraph(Figure 1) presented at the meeting. This viewgraph shows the DSS /AMSAC being pewered via a 4E0 volt bus with its own independent (i.e., not associated with the RTS) non-Class IE battery, rectifier and chstger i that provide 120 VAC to the ATWS circuitry, j

2. provide a power source to the DSS as discussed above but non-battery backed, in addition, provide a discussion showing that for all loss of offsite power scenarios, the rods will be released throagh a loss of voltage to the 480 VAC holding mechanism. Further:nore, show that the Emergency Feedwater Initiation and Control System (EFIC) design (oritsequivalent)meetstherequirementsoftheATWSRule(i.e.,

show that EFIC and AMSAC are equivalent in that they both perform the same function). If EFlc is powe ed through RTS 120 VAC buses then show by a f ailure modes and effects analysis that comon r.ede failures will not propa both EFIC and the RTS, gate through For this thetiepower case, supplies and disable EFIC system has to be a Class 1E system. .

3. Provide a Class 1E DSS that is powered by RTS sower sources and show through a failure modes and Mfee? inalysis tiat comon mode failures will not propsgate through ti.e owe. applies and disable both DSS and the RTS. EF1C is ta be t 'est.J as discussed in (2) atove.

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, .- 't L. C. Stalter .

Based on our discussions to date it is apparent that the i>ower supply issue  !

has delayed the implementation of the ATWS syste.a at the B4W plants. We are '

concerned over this delay and strongly recomend that the 8&W Iicensees proceed with their planned ATWS implementation utilizing the option that w111 support the quickest resolution of the power supply independence issue. Option 1 will provide the most expeditious resolution and would clearly meet the power supply '

independence guidance published with the ATWS Rule. The approaches specified in options 2 and 3 are significantly more complex in that they involve the development of specific detailed failure modes and effects analyses. Such .

approaches could significantly delay resolution of the power supply independence '

issue (separationissue and may ultimately lead to non-acceptance by the staff j

should unacceptable fat ure modes be identified.

!~ Following receipt of each plant specific "cenceptual" design package, the staff plans to review the package within 30 days and to approve, or disapprove with i coments, the proposed design. This will be followed by the issuance of a safety evaluation upon receipt of a more detailed design package. Since the generic design review has now been completed and the options for resolving the power supply issue are sufficiently clear, we have concluded that the staff

' safety evaluation does not have to precede the implementation of the required ATWS equipment. In other words, our safety evaluation would be a ' post-imple-

mwntation" review. All B&W plants, upon receipt of the NRC approval of the conceptual design, should install the ATWS equipment during their next refueling -

outage. In special cases where this can't be accomplished, it should be l

brought to the attention of the staff for their review and approval per 10 CFR

! 50.62(d).

I i Sincerely, i b/

Gary Holahan, Acting Director Division of Reactor Projects - !!!, IV,

' V and Special Projects O!fice of Nuclear Reactor Regulation i

Enclosures:

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