ML20091J366

Application for Amend to License NPF-18,revising Tech Specs to Include Reactor Scram on Low CRD Pump Discharge Pressure. Class III Fee Encl

ML20091J366
Person / Time
Site:	LaSalle
Issue date:	05/24/1984
From:	John Marshall COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20091J371	List: ML20091J366 ML20091J382
References
8671N, NUDOCS 8406050488
Download: ML20091J366 (3)

Text

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/ 'N Commonwealth Edison

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. ) one First Nrtionti Ptua, Chicago, Ilknois (x 7 Address Riply to: Post Office Box 767

/ Chicago Illinois 60690 May 24, 1984 Mr. Harold R. Denton, Director Of fice of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

LaSalle County Station Unit 2 Proposed Amendment to Technical Specification for Facility Operating License NPF-18 Reactor Scram on Low Control Rod Drive Pump Discharge Pressure Modification NRC Docket No. 50-374 References (a): NPF-18 License Condition 2.C(7) Low Pressure in Pump Discharde of the Control Rod Drive.

(b): FSAR Section 4.6.2 pages 4.6-9, 26, 31.

(c): FSAR Section 7.2 pages 7.2-8, 10, 65, 65a, 65b, 65c, 92, 93, Figure 7.2-5.

(d): SSER #2 4.6.2, Control Rod System.

(e): SSER #7 7.2, Control Rod Drive Low Charging Pressure Scram.

Dear Mr. Denton:

Pursuant to 10 CFR 50.59, Commonwealth Edison proposes to amend Appendix A, Technical Specification, to Facility Operating License NPF-18. These amendment changes are being submitted for your staff's review and approval in accordance with one of the conditions as contained in this license.

l The proposed change is enclosed in Attachment 2. The attached change has received both On-Site and Off-Site review and approval. We have reviewed this amendment request and find that no significant hazards consideration exists. Our review is documented in Attachment 3.

Commonwealth Edison is notifying the State of Illinois of our request for this amendment by transmitting a copy of this letter and its attachments to the designated State Official.

8406050498 840524 PDR ADOCK 05000374 P PDR I !

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. 1 H. R. Denton May 24, 1984 We have determined that this request is a 10 CFR 170, Class III amendment request. As such a fee remittance of $4,000.00 is enclosed.

Please direct any questions you may have concerning this matter to this office.

.Three (3) signed originals and thirty-seven (37) copies of this transmittal and its attachments are provided for your use.

Very truly yours,

. 90. M J. G. Marshall Nuclear Licensing Administrator Attachments (1): Background (2): Technical Specification Change to NPF-18 (3): Evaluation of Significant Hazards Consideration cc: Region III Inspector - LaSalle A. Bournia - NRR G. Wright - Ill.

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SUBSCRIBED and.SW RN to before me this T day of d au/ , 1984

d. hO Notary Public 8671N 3

l ATTACHMENT 1 Technical Specification Change Request LaSalle County Station Unit 2 BACKGROUND The control rod drive (CRO) system provides high pressure charging water to.the under-piston area of the control rod drive

. mechanisms to scram the reactor when required. If the charging water header pressure is lost, the individual scram accumulators provide a source of energy to perform the scram function. Check valves are located between the accumulators and the charging water header. These check valves maintain the accumulators pressurized following a loss of charging water pressure. If a check valve leaks after charging water is lost, the accumulator pressure could decrease below the pressure required to insert the control rod if the reactor pressure is insufficient to provide a source of high pressure water to accomplish to scram function (startup and refueling modes).

There is a concern when the reactor vessel is at less than operating pressure, (less than 950 psig) that the control rod drive accumulators do not maintain adequate pressure for a period of time compatible with operator action if no control rod drive pump is operating (reference (d)). With reactor pressure greater than 950 psig, charging cater pressure is not of concern because reactor pressure is sufficient to ensure adequate scram capability.

DISCUSSION To ensure that sufficient high pressure water is available for a scram in the startup and refueling modes, a reactor trip (SCRAM) on low

-CRD pump discharge water header pressure has been designed and is being installed in LaSalle County Unit 2 (References (a), (b), (c), and (e)).

The proposed Technical Specification change (Attachment 2) is in accordance with the setpoints and conditions as discussed and approved in ,

SSER 7 (Reference (e)). This provides for a Control Rod Drive charging water header low pressure SCRAM with a trip setpoint of greater than or equal to 1267 psig (allowable value 1185 psig) with a time delay of less n' than or. equal to 10 seconds. This scram will be automatically bypassed chen the reactor mode switch is in other than the startup or refuel positions (Operational Conditions 2 and 5). The surveillance requirement 4.1.3.5.b.2 to " measure and record the time that each individual accumula-tor pressure above the alarm setpoint with no control rod drive pump operating" is no longer required because the worst case leakage rate of the accumulator check still provides sufficient pressure to insert the control rods with the charging water header low pressure scram in effect.

8671N e .