ML19323H726
| ML19323H726 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 06/09/1980 |
| From: | Vandenburgh D Maine Yankee |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-12, WMY-80-90, NUDOCS 8006160110 | |
| Download: ML19323H726 (2) | |
Text
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DWE/JHM UDI B.4.1.1 DEM/EWJ KMY 80-90 United States Nuclear Regulatory Commission Omce of Inspeedon and Enforcement CDF-2(MY) eg nI PAB 631 Park Avenue King of Prussia, Pennsylvania 19406
!Nention:
Mr. Boyce H. Grier A
References:
(a) License No. DPR-36 (Docket No. 50-309)
- A" (b)
IE Bulletin No. 80-12 " Decay Heat Removal System E*"*
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Dear Sir:
CEMonty JBRanda::a
Subject:
Decay Heat Removal System Operability DCLaubenstein JRitsher Maine Yankee has completed the reviews and analyses requested by Reference Chron (b). The results of these reviews and analyses are discussed below, nu=bered L1:ensing to correspond to the referenced Bulletin.
Filo Copy 7.a. In addition to the high degree of redundancy (discussed below) of the Maine Yankee Residual Heat Removal (RHR) System, the reviews required by Reference (b) have shown that existing plant procedures and administrative controls recognize the importance of =aintaining the availability of RHR.
The Maine Yankee procedure for Plant Cooldown already contains provisions for blocking the Safety Injection Actuation System (SIAS). Blocking this system automatically blocks %ntainment Spray, Containment Isolation and ECCS Recirculation. Further, existing procedures require that when RHR is in service, with the head removed, the containment safeguards sump is isolated by manual isolation valves to prevent filling of the suction lines with air. Finally, existing plant procedures and specifications require at least one operable path for injection of borated water whenever there is fuel in the reactor.
In addition to the above, Maine Yankee shall implement administrative controls as necessary to insure that during refueling shutdowns, maintenance activities are not unnecessarily undertaken on co=ponents of the RHR system, or its support systems, during that period between when the Steim Generator is considered inoperable, and when the Reactor Vessel Head has been removed. These controls shall be implemented prior to the next refueling shutdown.
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U.S. Nuclear Regulatory Conmission June 9, 1980 Attention: Mr. Boyce H. Grier Page 2 7.b. Maine Yankee has never experienced a loss of RHR incident, and certain design features of the redundant RHR system at Maine Yankee make this an unlikely occurrence.
The Maine Yankee RHR system shares active components with the ECCS System and thus has a high degree of overall reliability. The redundant RHR pumps double as redundant Low Pre'sure Safety Injection pumps and, as s
such, are powered from separate and redundant' safeguards buses, each of which can be provided with power from separate and redundant backup diesel generators.
The redundant RHR heat exchangers double as redundant Containment Spray neat exchangers. Each is provided with cooling water from a separate source of Component Cooling.
Tne majority of the RHR System piping is shared witn portions of the Low Pressure Safety Injection and Contdn=ent Spray systems and, as such, has a high cegree of integrity.
Maine Yankee believes that the high degree of redundancy of the Maine Yankee RHR system design plus the administrative controls already in place and committed to via this letter provides adequate assurance of the continued reliability of the system. We trust this infor=ation is satisfactory. Should any additional information be required, please feel free to contact us.
Very truly yours, MAINE YANKEE ATOMIC POWER COMPANY b
D. E. Vandenaurgh Vice President COMM0!f4EALTH OF MASSACHUSETTS)
)ss COUNTY OF WORCESTER
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Then personally appeared before me, D. E. Vandenburgh, who, beint; duly sworn, did state that he is a Vice President of Maine Yankee Atomic Power Company, that he is duly authorized to execute and file the foregoing request in the namo and on tne behalf of Maine Yankee Atomic Power Company, and that the statements therein are true to the best of his knowledge and belief.
' Robert H. Groce Notary Public
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My Commission Expires September 14, 1984
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