ML20237J526
| ML20237J526 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/11/1987 |
| From: | George Thomas PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NYN-87094, NUDOCS 8708180210 | |
| Download: ML20237J526 (4) | |
Text
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George S. Thomas l
Vice President-Nuclear Production NYN-87094 Putl$c Service of New Hampshire "E
- New Hampshire Yankee Division United States Nuclear Regulatory Commission Washington, DC 20555 Attention: Document Control Desk
References:
Facility Operating License Ho. NPF-56, Construction Permit CPPR-136, Docket Nos. 50-443 and-50-444
Subject:
Revision of Initial Test Program
' Gentlemen:
.In accordance with the requirement.of the Seabrook' Station Operating License, Enclosure 1 provides an annotated copy of FSAR Chapter 14, Table 14.2-5, Startup Test Abstract for Control Rod Worth Measurement. provides the supporting safety evaluation which has determined that this change to the Initial Startup Program will not create any unreviewed safety concerns.
Formal update of the affected FSAR page(s) will be made in a future amendment.
Should you have any questions regarding this matter, please contact Mr. Warren J. Hall at (603) 474-9574, extension 4046.
i Very truly yours, f
/
+e George S. Thomas l
Enclosures cc:
Mr. Victor Nerses, Acting Director PWR Project Directorate I-3 i
Division of Projects I/II U.S. Nuclear Regulatory Commission Washington, DC 20555 Mr. William J. Russell o
Q Regional Administrator "b
U.S. Nuclear Regulatory Commission bo Region I 631 Park Avenue ogg King of Prussia, PA 19406 oo W4 Mr. Antone C. Cerne NRC Senior Resident Inspector so Seabrook Station l
Seabrook, NH 03874 1
]
80 G-L P.O. Box 300. Seabrook, NH 03874. Telephone (603) 474-9574
- C a
ENCLOSURE 1 TO NYN-87094 CHAPTER 14 REVISION l
l
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SB'1.& 2 FSAR Amendment 48 January 1983 T AB12 14. 2-5 (Sheet 23 of 53)
I 20.
CONTROL ROD WORTH MEASUREMENT l'
l
' Objective'
)
,To' determine the differential and integral reactivity worth of an indivi-dual. control rod, bank and to ensure proper shutdown margin.
Plant Conditions / Prerequisites The plant is critical at zero; power at the control rod configuration-specified by the startup sequence.
. Test Method
' Control rod worths will'be obtained.by maintaining a constant boron addition or dilution and compensating for the reactivity change by rod movement.. These changes in reactivity are recorded by.a reactivity computer and analyzed to obtain the control rod worths.
Analysis of the co lected data wi_11_be_
perf o_rmed_ to _ c_onfirm_ adequate _ shu_t_down_inar2Ln _
dditional control rod worth C_in6aissfe~nie6tsmay 'b'e' cond'uct'ed itliiiidg 'tI'.e' rod swap technique.
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- - - _ _ - _ - - - - ws ' ' - -_~m Acceptance Criteria The measured control rod worths are conservative with respect to the values assumed in Chapter 15 of the FSAR.
48
l ENCLOSURE 2 TO NYN-87094 SAFETY EVALUATION The Rod Swap method is an alternate way of measuring control rod worth. The method involves measuring the " reference bank" (the expected largest worth bank) using. standard dilution techniques and then swapping the " test banks" (remaining banks) with the reference bank. The control rod worth is then inferred from the position of the reference bank with the test bank fully inserted and a Rod Shadow factor supplied by the core designer. This technique for measuring rod worth has been used successfully at some Westinghouse plants over the past few years.
WCAP-9863-P-A, " Rod Bank Worth Measurements Utilizing Bank Exchange", May, 1982, documents the Westinghouse analytical and test methods.
Included in this topical report is a copy of the NRC letter documenting approval of Rod Swap for Westinghouse cores. This method is also one of the approved rod worth measurement techniques in ANSI /ANS 19.6.1, " Reload Startup Physics Tests for PWRs".
Utilizing the Rod Swap method does not invalidate any accident analysis assumptions or cause any deviation from existing operating procedures. Thus the probability and consequences of accidents previously evaluated in the FSAR are not increased nor will it create the possibility of an accident not evaluated in the FS AR.
Utilizing the Rod Swap technique does not operate the Rod Control Systera outside its design limits. Thus the probability and consequences of a malfunction of equipment important to safety will not be increased nor will it create the possibility of a malfunction not evaluated in the FSAR.
The Rod Swap method is conducted in compliance with Technical Specifications; therefore, it has been determined that the margin of safety defined in Technical Specifications will not be reduced.
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