ML20059N942

Advises of Resolution of Auxiliary Feedwater Issue,Per .Issue Concerns Ability of AFW Sys to Provide Flow to Steam Generators Following Pipe Break

ML20059N942
Person / Time
Site:	Calvert Cliffs
Issue date:	10/12/1990
From:	Mcdonald D Office of Nuclear Reactor Regulation
To:	Creel G BALTIMORE GAS & ELECTRIC CO.
References
NUDOCS 9010240139
Download: ML20059N942 (4)

Text

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R- y UNITED ST ATES '

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1' -October 12, 1990 j

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Docket Nos. 50-317 j u ,

and' 50-318 f

r Mr~..G. C. Creel

.Vice President . Nuclear Energy

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1 Baltimore Gas and Electric Company 4 'Calvert Cliffs Nuclear Power Plant MD:Rts. 2 & 4-P.-0.-Box 1535 0

. .Lusby, Maryland 20657

Dear Mr. Creel:

4 J

SUBJECT:

AUXILIARY FEEDWATER DESIGN COMMITMENTS - CALVERT CLIFFS NUCLEAR l 4

-POWER PLANT, UNITS 1 AND 2 3

By letter dated September 18, 1990, you informed the Nuclear Regulatory i

'Comission (NRC).that while you were reviewing the technical adequacy and  ;

1. licensing-basis;of your Auxiliary Feedwater (AFW) systems for Calvert Cliffs ~

c w ~ Units 1.and 2, you determined that the documentation of a certain issue was sunclear. The purpose of your letter was to inform the NRC of your resolution of the issue.;

The' issue concerns the ability of the AFW systems to provide flow to'the steam .

generators-following a pipe break anywhere in the. discharge piping of the AFW

. . pumps concurrent with a single active failure.-  ;'

Following.the-accident _at Three Mile Island,LUnit 2 (TMI-2), you were requested to evaluate the design of Standard Review Plan = (SRP)your AFW systems-_in-accordance Section 10.4'.9'and Branch Technical Positionwith (BTP) the criteria in -

10-1. Your March 9. -1981,Lresponse to this- request appeared to indicate that, y

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'withithe' proposed design and procedural changes that would be implemented, the d

' AFW systems would meet the criteria of!the SRP and'BTP. This was-found l

acceptable by the NRC' staff in its Safety Evaluation = dated May_8,1981.

Your September 18,;1990, letter clarifies that your. current AFW systems do not.

meet:all 'of the criteria of the' SRP and BTP. Specifically, when one unit is operating and the other unit is shut down with its motor-driven pump g '

, -ino urable, the operatinf unit's AFW system does not have the ability to cope. ,

witU a' pipe break everywiere in the discharge piping of the AFW pumps- '

concurrent with a single-active failure. You have noted .in your letter that the AFW~ systems,- asl modified following the- accident at TMI-2, are designed.to-function' following a break in -the high energy portion of the discharge line

concurrent:with a single active failure. For your AFW systems, you have-defined the.high energy portion of Lthe discharge piping as being only that <

' portion of the systems- from the check-valves inside containment to the steam generators._ The staff agrees with this definition when the units.are at_ power 90102401'39 90101*

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'Mr. G.'C. Creel

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l with the AFW systems secured.: However, during startup and shutdown of a unit l when an AFW system-is operating, the entire AFW system is considered high l

-energy. ,If credit is given to the presence of the cross-connect between the l

' discharge lines of the motor-driven AFW pumps and the motor-driven AFW pump. '

from the alternate unit is operable, the systems have the capability to provide

..V flow to the steam generators following a-break anywhere in the discharge piping i of the AFW pumps. Such a break would only be postulated during startup or i shutdown when an AFW system was operating. .l On September 19, 1990, a conference call was held between the NRC and -

Baltimore Gas & Electric Company -(BG&E) to discuss the issue. ' As a result of l the call, the staff concluded that the Units 1 and 2 AFW systems are not in ~ ':

-total conformance with the criteria of the SRP and BTP under certain l conditions; nevertheless, the staff concluded that your current design is. 'I acceptable and is consistent with what the staff has accepted on similar I plants licer.s&d prior to the issuance of the SRP and'BfP. However, it is our l

. understanding that BG&E is in the process of implementing procedural changes H and administrative controls to assure that the operability status of the l cross-connected motor-driven AFW pumps will be known by the control room ,

operators of both units.

ll We appreciate your bringing this issue to our attention and providing the-detailed information in your. September 18, 1990, letter to resolve any ,

uncertainties in the connitments made to and approved' by the NRC staff. We consider this-issue resolved. p Sincerely.

~

Daniel G. Mcdonald,' Senior Project Manager Project Directorate I-1 1 Division of Reactor Projects - I/II Office of Nuc_ lear Reactor Regulation

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\ , . e 3- , Mr; G. C. Creel' J

Baltimore Gas &' Electric Company- 4 Calvert Cliffs Nuclear Power Plant a

cc: 1 y Mr. William. T.'_ Bowen, President _ Mr. Joseph H. Walter

.Calvert County Board of Engineering Division  :)

. Commissioners 1 Public Service-Commission _of Maryland' Prince Frederick, Maryland ' 20678 American Building.

231 E. Baltimore Street  :

Baltimore, Maryland 2120E-34B6 D..A. Brune, Esq. . 1 n

General Counsel . ' . - '

Baltimore Gas and Electric Company Ms. Kirsten A. Burger, Esq. l P. 0.. Box 1475 .

Maryland- People's Counsel

. Baltimore, Meryla6d 21203 _ Americar Building, 9th Floor 1 231 E. Baltimore. Street Mr. Jay E. ' Silberg, Esq. Galtimore, Maryland 21202  :

Shaw, Pittman, Potts: and-Trowbridge i

'2300'N. Street, NW Ms. Patricia Birnie-

, Washington,~DC. 20037 Co-Director Maryland Safe Energy Coalition P. O. Box-902'

Ms. G.LL. Adams, licensing Columbia,-Maryland 21044 Calvert-Cliffs Nuclear Power Plant  !

MD Rts 2 &l4, P 0.. Box'1535 j lLusby, Maryland 20657 ' j' '

Resident-Inspector--

c/o U.S. Nuclear Regulatory Commission - '

P' O. Box 437-

Lusby, Maryland 20657 l Mr.

Richard McLean . - i

' Administrator - Radioecology -i

, Department of: Natural; Resources

.~ 580; Taylor- Avenue i a .Tawes State.0ffice Building '

PPER 83 l( t Annapolis ~, _ Maryland = 21401 p -

Regional Administrator, Region I U.S. Nuclear Regulatory Connission-475 Allendale Road' p ' King of Prussia, Pennsylvania 19406 i

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/ e Mr. G. C. Creel with.the AFW systems secured. However, during.startup and . shutdown of a unit i - when an AFW system is. operating the entire AFW system is consisdered high --

t energy. If credit is.given to the presence of the cross-connect between the discharge lines: of the motor-driven AFW pumps and the motor-driven AFWL pump from the alternate unit is operable, the systems have the capability to provide flow to the~ steam generators following a break anywhere in the discharge piping ..

'of the AFW' pumps. Such a' break would only be postulated during startup or j shutdown when an'AFW system was operating. '

On-September 19, 1990, a conference call was' held between.the NRC and 7 L Baltimore Gas & Electric Company (BG&E) to discuss the issue. As a result of s

'the call', the staff concluded that the Units 1 and 2 AFW systems are not in-total. confonnance with the criteria of the SRP and BTP under certain. -

a conditions; nevertheless, the staff concluded that your current design is.

O acceptable and is consistent with what the staff has accepted on similar ,

p plants licensed prior to the issuance of the SRP and BTP. However, it is' our l

understanding that BG&E is in the process of implementing procedural changes -

and administrative controls to assure that the operability status of the '

cross-connected motor-driven AFW pumps will be known by the control room operators of.both units.

We appreciate your bringing this issue to'our attention and providing the h detailed--information in your September 18,1990, letter to resolve any

' uncertainties in the commitments made to and approved by the NRC staff. We consider this issue resolved.

Sincerely, .

ORIGINAL slGNED BY Daniel G. Mcdonald, Senior Project Manager

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Project Directorate I-1 ,;

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