ML20117P932
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5 APR 141989 j
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a-MLMORANDUN FOR:
Robert A. Capra, Project Director Project Directorate I-1 Division of Reactor Projects - I/II l
FROM:
M. W. Hodges, Chief Reactor Systems Branch Division of Engineering i Systems Technology
SUBJECT:
CALVERT CLIFFS UNITS 1 AND 2 RESPONSE TO GENERIC LETTER 88-17 ON LOSS OF DECAY HEAT REMOVAL WITH RESPECT TO EXPEDITIOUS ACTIONS Plant Name:
Calvert Cliffs Nuclear Power Plant Units I and 2 Docket Nos.:
50-317, 50-318
' TAC Nos.:
69730, 69731 Project Directorate:
Project Directorate I-1 Project Manager:
S. McNeil Review Branch:
SRXB/ DEST Review Status:
Complete for 60 day response, 90 day response pending The Reactor Systems Branch, DEST, has reviewed the submission by Baltimore Gas and Electric, dated January 3,1989 in response to Generic Letter 88-17 for l
expeditious actions for loss of decay heat removal.
This was for their l
Calvert Cliffs Units 1 and 2 plant.
L Based on our review of the licensee's submittal we have found that the response appears to meet the intent of the generic letter with respect to expeditious-l actions. The response was brief for a few items and therefore did not address all items in detail. We intend to audit both the response to these expeditious actions and the forthcoming responses on the progransned enhancements.
l We have enclosed comments in the form of a draft letter which can be adopted for mailing to the licensee. No licensee response to the letter is expected.
A SALP evaluation is also enclosed. These TACs will not be closed until the programmed enhancements (90 day response) are implemented.
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orYul thud by e,n.m M. W. Hodges,' Chief
- O Reactor Systems Branch i
M Division of Engineering & Systems Technology
Enclosure:
DISTRIBUTION As stated Central Files 1
SRXB R/F j
cc w/ enclosure:
MWHodges
- t' A. Thadani C. Trammell TCollins B. Boger R. Jones HBalukjian Ob2 S. McNeil W. Lyon HBalukjian R/F
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Contact:
H. Balukjian, SRXB, x20888 l
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Docket Nos. 50-317, 50-318 i
Mr. Joseph A. Tiernan Vice President, Nuclear Energy Baltimore Gas and Electric i
Charles Center.
i P. 0. Box 1475 Baltimore, Maryland 21203 1
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Dear Mr. Tiernan:
SUBJECT:
C0FEENTS ON.THE BALTIMORE GAS AND ELECTRIC RESPONSE 2
i TO GENERIC LETTER 88-17 FOR THE CALVERT CLIFFS NUCLEAR POWER PLANT UNITS 1 AND 2 FOR EXPEDITIOUS ACTIONS FOR 4
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LOSS OF DECAY HEAT REMOVAL (TAC N05. 69730, 69731)
Generic Letter (GL) 88-17 was issued on October 17, 1988 to address the i
potential loss of decay heat removal (DHR) during nonpower operation.
In the f
GL, we requested (1) a description of your efforts to implement the eight l
recommendedexpeditiousactionsoftheGLand(2)adescriptionofthe l
cnhancements, specific plans and a schedule for implementation of the six recommended program enhancements.
l 1
i The NRC staff has reviewed your response to Generic Letter 88-17 on expeditious
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actions in the letter of January 3,1989. We find that it appears to meet the intent of the generic letter with respect to expeditious actions.
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Your response is brief for a few items and therefore does not allow us to
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fully urderst nd your actions taken in response to GL 88-17. You may wish to l-consider several observations in order to assure yourselves that the actions are adequately addressed:
i 3.
You mention discussion of the Diablo Canyon event with operations l
personnel and appropriate personnel of your staff.
It is not specifically stated that maintenance personnel are also included. The j
item was intended to include all personnel who can affect reduced
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inventory operation.
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2.
You indicate that Calvert Cliffs has a permanently installed Refueling j
Level' Indicator provided by a pressure transmitter which senses off the bottom of one hot leg (opposite the hot leg that the shutdown cooling l
(SDC) system takes suction on).
The transmitter is referenced to V
i-I'
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-2 containment pressure.
Indication is provided in the control room by a digital meter and recorder.
You did not mention that an alarm is provided. Also, you indicate that a tygon tube level indication is connected to the same tap as the Refueling Level Indicator and provides local (in-containment) indication of RCS level.
Because of the comon tap, care must be taken to avoid a comon error.
In addition you mention that the Reactor Vessel Level Monitoring System (RVLMS) uses heated /
unheated junction thermocouples for eight discrete level increments. This system is only available when the reactor vessel head is installed and the 1
instrumentation is electrically connected.
You state that in the event of RCS pressurization the Refueling Level Indication would not be accurate j
since the instrument is referenced to containment pressure. However, you state that the RVLMS is accurate and is maintained in operation with the reactor vessel head on. This can provide a check at the discrete level increments. The accuracy of the RYLMS is not provided. When two or more level instruments are in place, care should 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 approxmiate the pressure of the void in the hot leg or be compensated to obtain the correct level value.
3.
Walking the tygon tube following installation to verify lack of kinks or loop seals is necessary. Experience shows that periodic walkdowns are needed after installatici We recomend daily walkdowns when the tygon tube is in use, with an additional walkdown imediately 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
. 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 at this time.
As you are aware, the expeditious actions you have briefly described are an interim measure to achieve an immediate reduction in risk associated with reduced inventory operation, and these will be supplemented and in some cases replaced by prograrned enhancements. We intend to audit both your response to the expeditious actions and your programmed enhancement program. The areas where we do not fully understand your responses as indicated above may be covered in the audit of expeditious actions.
This closes out the staff review of your responses to the expeditious actions listed in the GL. The area of programmed enhancements will be addressed in a separate letter.
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ENCLOSURE 2 i
SYSTEHATIC ASSESSHENT OF LICENSFE PERFORMANCE FACILITY NAME Calvert Cliffs Nuclear Power Plant Units 1 and 2 l
SUMMARY
OF REVIEW The Reactor Systems Branch, DEST, has reviewed the submittal by Baltimore Gas and Electric in response to Generic Letter 88-17 for expeditious actions with respect to loss of decay heat removal. This is for their Calvert Cliffs Units 4
I and 2 plants. We have found that their responses appear to meet the intent of the generic letter with respect to the expeditious actions.
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t!ARRATIVE DISCUSSION Of LICENSEE PERFORMANCE - FUNCTIONAL AREA The submittal for this response was received in the time frame stipulated.
The responses were for the most part complete but brief for a few items and therefore did not address all items in detail. We have provided observations for improvement and intend to follow up by auditing all the expeditious actions provided by Calvert Cliffs as well as the other licensees.
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AUTHOR:
H. Balukjian DATE:
4/11/89
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