ML20095C212

Submits Response to NRC Request for Addl Info Re Amend to Facility Operating License R-37,on Surveillance Frequency Requirement for Testing of Emergency Battery

ML20095C212
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	12/08/1995
From:	Bernard J, Lau E, Newton T MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CAMBRIDGE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9512110417
Download: ML20095C212 (2)

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• NUCLEAR REACTOR LABORATORY AN INTERDEPARTMENTAL CENTER OF d i.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY O. K. HARUNG 138 Albany Street. Cambridge. Mass. 02139-42 % J. A. BERNARD, JR.

Director Telefax No. (617) 253-7300 Director of Reactor Operations Telex No. g4 Tel. No. (6 /)g,gMIT-CAM 2

December 8,1995 U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Document Control Desk

Subject:

Respouse to NRC Request for Additional Information Dated September 8,1995 Regarding Amendment To Facility Operating License No. R-37, Docket No. 50-20, on

" Surveillance Frequency Requirement for Testing of the Emergency Battery."

Gentlemen:

The Massachusetts Institute of Technology (MIT) hereby submits this letter in response to the NRC Request for AdditionalInformation dated September 8,1995 to amend MITR Technical Specification #4.3.5 of Facility Operating License No. R-37.

Sine rely, fft- C.-Nr domas II. Newton, Jr. Edward S. Lau Assistant Superintendent for Assistant Superintendent for Reactor Engineering Reactor Operations MIT Reseamh Reactor MIT Reseamh Reactor ck 4 John A. Bemard, Ph.D.

Director of Reactor Operations MIT Research Reactor CIJgw cc: A. Adams. - NRC USNRC - Senior Project Manager.

NRRMNDD USNRC - Region I - Project Scientist, Effluents Radiation Protection Section (ERPS)

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i Response to NRC Request for Additional Information Dated September 8,1995 Massachusetts Institute of Technology Research Reactor Docket No. 50-20 The following addresses the three questions that were raised in the September 8,1995 NRC correspondence:

Response to Question #1. We agree with the NRC recommendation to change the surveillance frequency of the emergency battery discharge test from the current "once every two years" to "once every year." MITR intemal procedures call for an emergency battery discharge test be performed annually. This approach has the advantage of verifying the i operability of the entire emergency battery system once a year. Accordingly,it is proposed {

that TS #4.3.5 in Appendix A of Facility operating Liwnse No. R-37 be amended to read: l

5. The voltage of the emergency batteries shall be measured weekly whenever the reactor is scheduled to operate any day of that week. The voltage and specific gravity of one cell shall be measured monthly whenever the reactor is scheduled to j operate any day of that month. Specific gravity of all batteries shall be measured at 1 any time a significant change is noted in the pilot cell and at least once a year.

Discharge tests shall be performed once a year. Operability of the inverter motor-  ;

generator set and associated switches shall be verified quarterly.  !

l For your convenience, we have underlined the words that change the surveillance frequency j of the discharge test which includes measurement of the specific gravity on all batteries to be  ;

performed annually. l Response to Question #2. As explained in the response to the third question below, failure of the emergency battery to operate upon demand has no impact on safety. MITR Technical Specification #3.7 item #3 states that " Emergency power with the capacity to operate the equipment listed in Table II shall be available whenever the reactor is operating and shall be capable of operation for at least one hour following a loss of normal power to the facility."

Thus the requirement for the emergency battery to be operable is only meaningful for those situations in which the reactor is at power or has been at power within the last hour.

Therefore, there is no real need for performance of a surveillance test to verify operability of the emergency battery for the time periods in which the reactor is not scheduled to be at power. It will b sufficient to perform such tests (battery voltage and specific gravity measurement of the pilot cell) prior to reactor operation and at least once monthly. ,

Moreover, as noted in the response to Question #3 below, the emergency battery is not necessary for either personnel or reactor safety..

Response to Question #3. Thera is no safety significance should the emergency battery fail to operate when called upon. Two issues are involved: personnel safety and reactor safety.

'Ihe former is addressed through the use of battery-operated emergency lights that are located throughout the reactor building and through the use of battery-operated portable radiation detectors that could be used to identify radiation hazards if any. The latter is addressed through the design of the reactor which provides sufficient natural circulation for I the removal of decay heat following an extended period of operation at full power. Forced circulation through the reactor core is not required when the reactor is shutdown. Tests were conducted that demonstrated the adequacy of the natural circulation for decay heat removal as part of the MITR Startup Testing in 1973-74. Details were previously provided to the NRC (MITR Startup Report, Section #5.11.2). A copy of the relevant pages is  :

attached I

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