ML20039B338
| ML20039B338 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 12/16/1981 |
| From: | Garrity J Maine Yankee |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| TASK-2.K.3.30, TASK-TM 811816, FMY-81-181, JHG-81-225, NUDOCS 8112220548 | |
| Download: ML20039B338 (2) | |
Text
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n JARHEE Amml0P0lilERC0mPARU*
,ugugrgj,?n"gys MAIRE (207) 623 4521
-e December 16, 1981 FMY-81-181 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Office of Nuclear Reactor Regulation si fs Mr. Robert A. Clark, Chief W
9 Operating Reactors' Branch 3
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Division of Licensing
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References:
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License No. OPR-36 (Docket No. 50-309)
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Letter, MYAPCO to USNRC, dated November 21, 1980,
Subject:
NRC Action Plan Item II.K.3.30; Revised Small Break LOCA Methods (WMY 80-153)
Subject:
NRC Action Plan Item II.K.3.30; Revised Small Break LOCA Methods.
Dear Sir:
Maine Yankee via Reference (b) transmitted the scope and the schedule of the proaram to be pursued in resolving the ECCS model concerns as identified by the Action Plan Item II.K.3.30.
We had planned on pursuing two parallel approaches. One approach involved revision of the currently licensed RELAP4-EM Code.
The other involved the development and oualification of an EM i
package based on the RELAPS computer code.
The fin:d selection was to be based on various modeling requirements, accurate prediction of experiments, and~ user oriented features. We anticipated (ref, b) that the selection effort as well as the code modifications effort would be completed by January 1,1982.
Since the issuance of our letter (ref. b), RELAP5 was selected. Various versions of RELAPS we-obtained from INEL as soon as they were made available to outside users. ht
- c. needing improvements were identified, in addition to the development work needed to incorporate EM requirements.
Integral as well as separate effect tests were selected for the qualification of the code, and preliminary results have been obtained.
hoY Our experience exercising RELAP5 against various integral and separate j
effect tests! indicates that several of the constitutive equations in the code
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as released ~tiy"INEL (e.g., interphase drag, critical heat flux, heat transfer l/O logic) could be further improved.
In addition, solution algorithms stability, (e.g., boil-off under low flow conditions), are being given further attention. We have revised the work scope beyond that originally planned tc address these areas; as a result, the schedule has slipped.
8112220548 811216 PDRADOCK05000g P
M AINE YANKEE ATOMIC POWER COMPANY U. S. Nuclear Regulatory Commission December 16, 1981 Page Two Our RELAPS model submittal in response to Action Plan Item II.K.3.30 has, therefore, been rescheduled to April 16, 1982. We have discussed this matter with Dr. Brian Sheron of your staff.
We trust this information will be satisfactory; however, if you h ave any questions, please contact us.
Very truly yours, MAINE YANKEE ATOMIC POWER COMPANY rf h \\/
N John H. Garrity, Di ector Nuclear Engineering and Licensing