ML19325F263

Advises That Although Util 890103 Response to Generic Ltr 88-17 Re Loss of DHR Considered Brief & Did Not Allow NRC to Fully Understand Actions to Be Taken,Response Sufficient So No Further Response Presently Necessary.Observations Encl

ML19325F263
Person / Time
Site:	Calvert Cliffs
Issue date:	11/14/1989
From:	Mcneil S Office of Nuclear Reactor Regulation
To:	Creel G BALTIMORE GAS & ELECTRIC CO.
References
GL-88-17, TAC-69730, TAC-69731, NUDOCS 8911200019
Download: ML19325F263 (5)

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PDI-1 R/F OGC (info. only) l Mr. G. C., Creel, l,

SYarga EJordan Vice President - Nuclear Energy BBoger BGrimes

.i Baltimore Gas.and Electric Company RCapra ACRS(10) d Calvert Cliffs Nuclear Power Plant JWiggins PLANT FILE MD Rtes. 2 & 4 l

4 P. O. Box 1535' i

Lusby, Maryland 20657

SUBJECT:

RESPONSE TO GENERIC LETTER 88-17 FOR CALVERT CLIFFS 1 AND 2 WITH RESPECT TO EXPEDITIOUS ACTIONS FOR LOSS OF DECAY HEAT REMOVAL.(UNIT 1 TAC 69730; UNIT 2 TAC 69731) i actions contained in Generic Letter (GL)ponded to the request for expeditious By' letter dated January 3,1989, you res 88 17 The NRC staff has reviewed your response and finds that it meets the intent of the generic letter with respect i

to expeditious actions, i

I Although your response was brief and did not allow us to fully understand the i

actions to be taken in response to GL 88-17, your res>onse was sufficient so

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that a further written response is not necessary at tiis time. However, the NRC staff did make several observations that you may wish to consider in order to. assure yourselves that the actions are adequately addressed. The staff's 1

observations are provided in Enclosure 1.

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As you are aware, the expeditious actions you briefly described in your i

• January 3,in risk associated with reduced inventory operation 1989 response are an interim measure to achieve an immediate i

reduction these will be supplemented and in some cases replaced by programmed enhancements. We intend I

Lto audit both your response to the expeditious actions and your programmed

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enhancements. The areas where we do not fully understand your response as e

indicated in the enclosed observations, may be covered in the audit of expeditious actions.

I Sincerely, N

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~oo Scott Alexander McNeil, Project Manager o,b Project Directorate I-1 l

1 Division of Reactor Projects - I/II l

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Enclosure:

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. Mr. G. C. Creel Vic President - Nuclear Energy Baltimore Gas and Electric Company i

L Calvert Cliffs Nuclear Power Plant MD Rtts. 2 & 4 l

P. O. Box 1535 j

Lusby, Maryland 20657 l

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Dear Mr. Creel:

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SUBJECT:

RESPONSE TO GENERIC LETTER 88-17 TOR CALVERT CLIFFS 1 AND 2 WITH RESPECT TO EXPEDITIOUS ACTIONS FOR LOSS OF DECAY HEAT REMOVAL (UNIT 1 TAC 69730 UNIT 2 TAC 69731) j By letter dated January 3,1989, you res actionscontainedinGenericLetter(GL)pondedtotherequestforexpeditious 88-17. The NRC staff has reviewed your l

response and finds that it meets the intent of the generic letter with respect i

to expeditious actions.

l Although your response was brief and did not allow us to fully understand the I

actions to be taken in response to GL 88-17, your response was sufficient so i

that a further written response is not necessary at this time. However, the NRC staff did make several observations that you may wish to consider in order l

to assure yourselves that the actions are adequately addressed. The staff's observations are provided in Enclosure 1.

I l

As you are aware, the expeditious actions you briefly described in your

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January 3,in risk associated with reduced inventory operation; these will be 1989 response are an interim measure to achieve an imediate i

reduction i

supplemented and in some cases replaced by programmed enhancements. We intend to audit both your response to the expeditious actions and your programed enhancements. The areas where we do not fully understand your response as indicated ih the enclosed observations, may be covered in the audit of expediticus actions.

l Sincerely, l

l A=4Y l

Scott Alexander McNeil. Project Manager Project Directorate 1-1 l

Division of Reactor Projects - 1/l!

Office of Nuclear Reactor Regulation

Enclosure:

NRC Staff Observations Ne"hkhah'

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Mr. G. C Creel Baltimore Gas & Electric Company Calvert Cliffs Nuclear Power Plant CC:

k Mr. William T. Bowen, President Mr. Joseph H. Walter Calvert County Board of Engineering Division Comissioners Public Service Comission of Maryland i

Prince Frederick, Maryland 20678 American Building 231 E. Baltimore Street Baltimore, Mary 1cnd 21202-3486 l

General Counsel Baltimore Gas and Eltetric Company Ms. Kirsten A. Burger, Esq.

P. D. Box 1475 Paryland People's Counsel Baltimore, Maryland 21203 American Building, 9th Floor 231 E. Baltimore Street Mr. Jay E. Silberg, Esq.

Baltimore, Maryland 21202 i

Shaw, Pittman, Potts and Trowbridge i

2300 N Street, NW Washington, DC 20037 Mr. W. J. Lippold, General Supervisor Technical Services Engineering Calvert Cliffs Nuclear Power Plant MD Rts 2 & 4, P. O. Box 1535 Lusby, Maryland 20657 i

Resident Inspector c/o U.S. Nuclear Regulatory Comission P. O. Box A3' Lusby, Maryland 20657 i

t Mr.. Thomas Magette i

Administrator - Nuclear Evaluations Department of Natural Resources l

580 Taylor Avenue Tawes State Office Building PPER B3 i

l Annapolis, Maryland 21401

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Regional Administrator, Region I V.S. Nuclear Regulatory Comission l

475 Allendale Road King of Prussia, Pennsylvania 19406

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ENCLOSURE 1 1

i NRC STAFF OBSERVATIONS OF RESPONSE TO GENERIC LETTER 88-17

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i 1.

You mention discussion of the Diablo Canyon event with operations personnel and appropr16te personnel of your staff, it is not specifically i

stated that maintenance personnel are also included. The item was intended to include all personnel who can affect reduced inventory j

operation.

i 2.

You indicate that Calvert Cliffs has a permanently installed Refueling l

Level Indicator provided by a pressure transmitter which senses off the i

bottom of one hot leg (opposite the hot leg that the shutdown cooling (3DC) system takes suction on).

The transmitter is referenced to containment pressure.

Indication is provided in the control room by a i

digital meter and recorder. You did not mention that an alarm is i

provided. Also, you indicated that a tygon tube level indication is connected to the same tap as the Refueling Level Indicator and provides i

local (in-containment) indication of RCS level, Because of the common j

tap, care must be taken to avoid a comon error.

In addition you mention i

that the Reactor Yessel Level Monitoring System (RILMS) uses heated /

unheated junction thermocouples for eight discrete level increments, i

This system is only available when the reactor vessel head is installed and the instrumentation is electrically connected. You state that in the event of RCS pressurization the Refueling Level Indication would not be accarate since the instrument is referenced to containment pressure, i

However, you state that the RVLMS is accurate and is maintained in i

operation with the reactor vessel head on. This can provide a check at the discrete level increments. The accuracy of the RVLMS is not provided. When two or more level instruments are in place, care should i

be taken to resolve any discrepancy between the measurement systems.

Also, for the level instruments using pressure taps the pressure of the reference leg should approximate the pressure of the void in the hot leg or be compensated to obtain the correct level value, j

3.

Walking the tygon tube following installation to verify lack of kinks or i

loop seals is necessary. Experience shows that periodic walkdowns are needed after installation. We recomend daily walkdowns when the tygon tube is in use, with an additional walkdown immediately prior to its being placed in use.

4 You state that "the SG nozzle dam maintenance procedure will require an adequate RV head vent prior to installing all SG hot leg nozzle dams."

You have not stated what this vent opening is.

Often a pressurizer manway or steam generator manway is used as a means to provide RCS venting. We note that relatively large hot side openings in the RCS, such as a

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pressurizer manway, can still lead to a pressure of several psi. The large steam flow in combination of flow restrictions in the surge line and lower pressurizer hardware may lead to pressurization. Calculations should be performed to verify the effectiveness of the opening.

There is no need to respond to the above observations.