B13337, Summary Rept,Cycle 13 Start-Up Physics Testing

Summary Rept,Cycle 13 Start-Up Physics Testing

ML20245K694
Person / Time
Site:	Millstone
Issue date:	08/15/1989
From:	Mroczka E, Romberg W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:
References
B13337, NUDOCS 8908210119
Download: ML20245K694 (4)

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General Offices

• Seiden Street, Berlin, Connecticut

" P.O. BOX 270 g . I.sIu'r$n a cE , HARTFORD. CONNECTICUT 06141-0270 k U aummm or.a.a i uvaco-=v (203) 665-5000 August 15, 1989 Docket No. 50-245 B13331 Re: Specification 6.9

' U.S. Nuclear Regulatory Commission Attention: Document Ccntrol Desk Washington, DC 20555 Gentlemen:

Millstone. Nuclear Power Station, Unit No. 1 Start-Up Physics Testina Procram for Cycle 13 Pursuant to Millstone Unit No. I's Technical Specifications, Section 6.9, enclosed please find a summary report of the Cycle 13 Start-Up Physics Test resu'l ts . In keeping with established practice, this report has the same basic format and content as submitted for the last several fuel cycles.

Shoald you have any questions on the enclosed summary report, please feel free to contact my staff.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY E 7 !""c e /G E. J. Mroczka Senior Vice President NO jC l By: W. D. RomberV Vice President cc: W. T. Russell, Region I Administrator M. L. Boyle, NRC Project Manager, Millstone Unit No. I W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos. 1, 2, and 3 l

't 8908210119 890815 PDR ADOCK 05000245 P PDC

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.. i e-r Docket No. 50-245 B13337 Millstone Nuclear Power Station, Unit No 1 Summary Report Cycle 13 Start-Up Physics Testing l

August 1989 iFN

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E U.S. Nuclear Regulatory Commission BI3337/ Enclosure /Page 1 August 15, 1989 MILLSTONE UNIT NO. 1 CYCLE 13 START-UP PHYSICS TESTING REACTOR CORE VERIFICATION At the completion of fuel loading, the reactor core was videotaped and veri-fied. Fuel assembly location, seating,.and rotation were found to be correct.

COLD CONTROL R0D DRIVE TESTING At the completion of core verification and vessel reassembly, each control rod underwent functional and subcritical testing. No unacceptable conditions were

. identified.

During this testing, control rod drives in core. locations 14-03 and 38 03 were found to have insert 'and withdrawal speeds in excess of specified limits. The speeds were analyzed as being acceptable based on the control rods being Ir,cated on the core periphery and being designated for withdrawal in the first rod group to be withdrawn from the core during a start-up sequence.

The rod settle function of control . rod drive 30-15 was found to be question-

. abl e . During initial testing, the drive did not settle into all notch posi-tions. Additional diagnostic testing was performed to verify that this problem was not a result of binding of the control rod in the core region, and the condition was analyzed as being acceptable based on the ability of causing the settle function to occur by lowering the drive water pressure during withdrawal of the control rod drive. During rod withdrawal at elevated reactor pressure in the start-up _ sequence, however, the control rod drive functioned normally.

l HOT CONTROL R0D DRIVE SCRAM TIME TESTING With the reactor at hot operating conditions, each control rod was indi-vidually scrammed and timed. The following results were obtained:

Technical Percent- Specification Average Actual Inserted _. Time (Sec) Time fSec)___

l-5 0.375 0.305 20 0.900 0.693 50 2.000 1.436 90 3.500 2.533 The average 5, 20, 50, and 90 percent scram times for the three fastest control rods in a two-by-two array were also compared to Technical Specifica-tion limits. No discrepancies were noted.

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h U.S. Nuclear Regulatory Commission B13337/ Enclosure /Page 2 August 15,.1989 i

SHUTDOWN MARGIN TEST Shutdown margin demonstration was performed using the in-sequence critical data method during the initial Cycle 13 criticality. The results indicated that the reactor core at B0C 13 had a shutdown margin of 1.55 percent delta k/k. The required shutdown margin at BOC 13 was 0.97 percent based on

-the Technical Specification limit of 0.33 percent and an analyzed decrease in shutdown margin of 0.64 percent between B0C 13 and the most reactive point in the fuel cycle.

NONVOIDED CRITICAL EIGENVALUE COMPARIS0N FOR A FIXED CONTROL R0D PATTERN The expected critical control rod pattern was compared to the actual critical control rod pattern. The actual control rod pattern required 208 additional notches to be withdrawn to achieve core criticality. The reactivity associ-ated with these additional notches is approximately 0.25 percent delta k/k and is not considered to be an anomaly.

CRITICAL R0D CONFIGURATION COMPARIS0N AT RATED REACTOR CONDITIONS At 100 percent power and core equilibrium conditions, the actual control rod pattern was compared to the predicted control rod pattern for B0C 13 opera-tion. The actual number of control rod notches inserted in the core was 472 as compared to 454 notches predicted to be inserted. The reactivity associ-ated with the 18 additional notches is well within the Technical Specification limit of 1 percent delta k/k and is not considered to be an anomaly. (For Cycle 13 operation at rated conditions, 377 notches is equivalent to 1 percent delta k/k.)

JET PUMP PERFORMANCE Jet pump baseline data was acquired during a pl9nned decrease in recirculation flow from rated, equilibrium conditions. The data, taken at reactor power intervals of approximately 10 percent until minimum recirculation pump speed was reached at 61 percent reactor power, were found to be acceptable. Data reduction showed that recirculation system performance was comparable to past cycle performance. Additionally, Recirculation System MG Set mechanical stop positions were verified to be adequate to maintain flows below 102.5 percent in the event of controller failure to maximum demand.

POWER DISTRIBUTION AND CORE PERFORMANCE COMPARIS0N AT RATED POWER At 100 percent power and equilibrium conditions, core power shape and margin to fuel thermal limits were compared to the predicted values and found to be acceptable. Differences from the predicted values were attributed to control rod pattern differences. The adjusted control rod pattern added operating flexibility and is considered to be acceptable.

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