ML20116G367
| ML20116G367 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 04/27/1985 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | John Miller Office of Nuclear Reactor Regulation |
| References | |
| NFM-85-156, NUDOCS 8505010460 | |
| Download: ML20116G367 (4) | |
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4 B ALTIMORE G AS AND ELECTRIC COMPANY P.O. B O X 147 5 B ALTIMOR E, M A R YLAN D 21203 NUCLEAR POWER DEPARTMENT -
CALVERT CLIFFS NUCLEAR POWER PLANT LUSBY, MARYLAND 20657 April 27,1985 NFM-85-156 U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, DC 20555
- ATTENTION: Mr. James R. Miller, Chief Operating Reactors Branch #3
.L Division of Licensing
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No.1; Docket No. 50-317 Responses to Questions - Unit 1, Cycle 8 License Submittal
REFERENCE:
(1)
A.E. Lundvall, Jr., to J.R. Miller letter dated 2/22/85, Eighth Cycle License Application (2)
R.A. Clark, to A.E. Lundvall, Jr. letter dated February 8,1982 Gentlemen:
This letter responds to verbal questions received in the course of NRC review of the Calvert Cliffs Unit 1, Cycle 8 Reload License Spmittal, Reference 1. Specifically, the questions pertain to the reanalysis of the 0.1 ft,Small Break Loss of Coolant Accident (SBLOCA) performed a part of the Unit 1 Cycle 8 reload evaluations. The questions and responses are provided in Attachment 1.
Should you have further questions regarding the license submittal, we will be pleased to discuss them with you.
- cerely, W
R. B. Denton General Supervisor Training & Technical Services RED /MEB/jes Att:
8505010460 850427 i %
PDR ADOCK 05000317
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Mr. Jem'es' R. Mill r April 27,1985 Page 2 ;
i-l ect D.i. Brune, Esq.
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- G.F. Trowbridge, Esq.
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D.H. Jaffe, NRC L T. Fole,r, NRC
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A'ITACHMENT 1 QUESTION: How was the 80% power threshold of proposed Technical Specifications 3.1.2.8 and 3.1.2.9 established?
RESPONSE: The reduction in the maximum allowed power to 80% with the less restrictive borated water source operability requirement reduces the decay heat rate during Small Break LOCA by 20% This reduces the boil off of the coolant inventory which can be equated to an inventory addition relative to the Small Break LOCA from full power.
This equivalent inventory addition was compared to that resulting from the charging flow credited for the 100% power analysis and found to be wellin excess of that due to the charging flow. Therefore the equivalent inventory addition for 80% power due to the reduced decay heat load more than makes up for that lost if charging is not credited. Therefore Small Break LOCA from 80%
power without any credit for charging flow is bounded by the analysis for Small Break LOCA from full power with credit for charging flow.
QUESTION: How will previous charging pump packing problems affect pump performance on SIAS and what has been done to resolve the earlier problems?
RESPONSE: The governing criteria for repacking of charging pumps relates to minimization of airborne contamination and not to reduction in charging pump capacity. The packing leakage at which a pump is considered for repacking is very small and results in essentially no reduction in the pump flow to the RCS. A pump with unacceptable leakage with respect to airborne contamination concerns may be stopped; however it will start on SIAS and provide adequate flow. Only one pump is taken out of service at a time for repacking and two charging pumps remain operable as is required by Technical Specification 3.1.2.4.
As of April 12, 1985, the run times for the six charging pumps at Calvert Cliffs since their most recent repacking are as follows:
PUMP HOURS 11 456 12 679 13 366 21 2,906 22 121 23 3,016
4
-It should be noted that the Unit I run times reflect the experience since these pumps were repacked with the material which Unit 2 experience has shown to be superior. The Unit 1 material conversion occurred during February and March and the pumps have been shutdown since refueling began in early April.
QUESTION: How is surveillance of response times of CVCS components that must operate on SIAS documented?
RESPONSE: The Tech. Specs. do not list individual ESFAS components response times.
Technical Specification Surveillance requirement 4.3.2.1.3. states "The Engineered Safety Features Response Time of each ESFAS function shall be demonstrated to be within the limit at least once per 18 months". The response time limits are given in Table 3.3-5.
of the Technical Specifications.
Surveillance Test Procedure (STP) 0-56 verifies that the Safety Injection (ECCS) components meet the time requirements of Table 3.3-5. Previously STP 0-56 verified the Safety Injection response time for the IIPSI pumps, LPSI pumps, and the valves associated with those systems. STP 0-56 is now being modified to include response time testing for the charging pumps, boric acid pumps and their associated flow path valves.
QUESTION: State whether performance testing of coolant charging pumps under Section XI of the ASME Boiler and Pressure Vessel Code is done on a monthly or a quarterly basis. If testing is done on a quarterly basis, provide justification.
RESPONSE: Performance testing of safety related pumps, including coolant charging pumps, is done on a quarterly basis. BG&E tests safety related pumps in accordance with Section XI of the ASME Boiler and Pressure Vessel Code, 1980 Edition, which is referenced by 10 CFR 50.55a and was approved for BG&E by NRC in Reference 2.
The 1980 Edition of the ASME Code requires a quarterly performance test.
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