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JAlt 13 :388 MEMOR/.NDUM FOR:
R. Capra, Project Director Project Directorate I-1 Division of Reactor Projects I/Il FROM:
M. W. Hodges, Chief Reactor Systems Branch Division of Engineering & Systems Technology
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION ON REACTOR COOLANT PUMP TRIP 0F CALVERT CLIFFS UNITS 1 AND 2 Plant Name:
Clavert Clifffs Units 1 & 2 Docket No.:
50 317 50 318 TAC No.:
49674 & 49675 i
Project Directorate:
Project Directorate I-1 Project Manager:
S. McNeil l
Review Branch:
SRXB/ DEST Review Status:
Incomplete I
i During the review of Reactor Coolant Pump Trip issue (TMI Action Item i
II.K.3.5) for Calvert Cliffs 1 & 2, our contractor EG&G determined that additional information is needed in order to complete the review. Please forward these questions to the licensee.
/5 M. W. Hodges, Chief Reactor Systems Branch Division of Engineering & Systems Technology
Enclosure:
As stated
Contact:
S. Wu, SRXB x24762 DISTRIBUTION Central' File T. Collins R/R I
SRXB R/F Calvert Cliffs P/F aM"'
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REQUEST FOR ADDITIONAL INFORMATION CALVERT C'.IFFS UNITS 1 AND 2 DOCKET NO. 50-317 and 50-318 RESPONSE TO GENERIC LETTER 86-06
" IMPLEMENTATION OF TMI ACTION ITEM II.K.3.5"
REFERENCES:
- 1. Telephone conference between BG&E, NRC, EG&G Idaho, Inc. " Clarification of Calvert Cliffs Response to Generic Letter 86-06", November 30, 1987.
- 2. Letter from J. A. Tiernan (BG&E) to A. C. Thadani (NRC), October 23, 1986.
- 3. Letter from J. A. Tiernan (BG&E) to A. C. Thadani (NRC), November 21, 1986.
- 4. Combustion Engineering Report CEN-268, March 1984.
- 5. Combustion Engineering Report CEN-268 Supplement 1-NP, November 1984.
QUESTIONS:
- 1. The Licensee's description [ref. 1] of the instrument' tion uncertainties a
for loop PT-105 differs from the material presented in previous letters
[ref. 2,3]. The Li,censee intends to use an uncertainty of approximately 212 psia during the first 5 minutes of a LOCA or non-LOCA transient.
After 5 minutes have passed an uncertainty of 423 psia will be used.
4 The Licensee needs to describe the basis for determining the 212 and 423 psia uncertainties for loop PT-105. Also, the Licensee needs to describe how the 5 minute switch point was determined.
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- 2. The generic responses to Questions 48-55 [ref.5] describe the major assumptions used in the CE analyses. The Licensee needs to review these assumptions and verify that they are valid for Calvert Cliffs.
The Licensee's response can be presented as a corresponding list of plant specific values, noting areas of conservatism. Any plant specific values that are less conservative than the generic analyses must be justified.
- 3. Section 5 of CEN-268 [ref. 4) evaluates sample transients that are representative of CE plants. The generic setpoints (1300 psia primary pressure and 20F subcooling margin) and the predicted system behavior were discussed. The Licensee needs to verify that the plant specific setpoints will not significantly affect the results of the generic analyses.
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- a. Verify that the generic assessment of each transient is valid for l
Calvert Cliffs, i.e., the time at which the Calvert Cliffs pumps are tripped (1725 psia setpoint plus uncertainty) is not significan.tly different from the time when the pumps are tripped for the generic I
case. The Licensee can express this assessment in terms of the appropriate transient curves, primary and secondary setpoints including uncertainty, system behavior, and availability of equipment, e.g., use of more than 1 HPI or make up pump during recovery from l
the transient.
- b. If the Calvert Cliffs assessment in (a) leads to different results
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than the generic report, (e.g., trip all 4 pumps at Calvert Cliffs instead of T2/L2 or trip 2 pumps instead of leave 4), then describe 4
the basis for acceptance. The Licensee should be mindful of meeting the intent of Generic Letter 86-06, namely " pumps will remain running for those nonLOCA transients and accidents where forced convection cooling and pressurizer pressure control would enhance plant control".
- 4. The Licensee indicated [ref.1] that implementation of the RCP trip strategy is consistent with the CE Report NPSD-151-P "CE Safety Analysis Methods for Calvert Cliffs Units 1 and 2". The Licensee is requested to provide an information copy of this document.
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