ML20209G373

Forwards AEOD/T510, Xenon-Induced Power Oscillations at Catawba, Technical Review Rept.Nrr Will Consider Including Reg Guide 1.68 Option of Referencing Prior Test Results in Lieu of Performing Actual Testing in Next Rev

ML20209G373
Person / Time
Site:	Catawba
Issue date:	09/04/1985
From:	Freeman R NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
To:	Seyfrit K NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
Shared Package
ML20209G379	List: ML20209G373 ML20209G401
References
AEOD-T510, NUDOCS 8509190249
Download: ML20209G373 (2)

Text

s. V D9-September 4, 1985 MEMORANDUM FOR: Karl V. Seyfrit, Chief AE0D/T510 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data THRU: Wayne D. Lanning, Section Chief Reactor Systems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data FROM: Robert G. Freeman, Engineer Reactor Systems Section 2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data

SUBJECT:

TECHNICAL REVIEW REPORT: XENON INDUCED POWER OSCILLATIONS AT CATAWBA Enclosed is AEOD technical review report entitled " Xenon Induced Power Oscillations at Catawba" for your consideration. On March 18, 1985, with Catawba Unit 1 at approximately 50% power, during initial startup physics testing, severe core power tilts and oscillations occurred as a result of control rod insertion testing. Because of unexpected equipment problems and lack of procedural guidance, a control rod remained inserted in the core for an extended period of time. Upon withdrawal of the control rod to its fully withdrawn position, severe xenon induced power oscillations were experienced which resulted in a reduction in reactor power operation and in the delay in the completion of-startup physics testing. The corrective actions taken by the licensee were judged to be appropriate. Testing procedures which address the maximum allowable time of control rod misalignment could significantly reduce the likelihood of inducing severe core power tilts and oscillations.

However, some of the physics tests the licensee was conducting appear to be superfluous. Allowing licensees to reference the results of tests at plants-with identical cores as an alternate to plant-specific testing will enhance reactor safety, and minimize the time required for conducting low power physics 8509190249 850904

{DR ADOCK 05000413 PDR i

l l

L 1

.a.

2 testing. Elimination of unnecessary testing would reduce the potential for xenon induced power oscillations, which when combined with a power transient, could cause local departure from nucleate boiling (DNB) limits to be exceeded.

Discussions with cognizant staff members in NRR indicate that NRR would be willing to consider including in its next revision of Regulatory Guide 1.68, the option of referencing prior test results in lieu of performing the actual "

testing.

/d Robert G. Freeman, Engineer Reactor Systems Section.2 Reactor Operations Analysis Branch Office for Analysis and Evaluation of Operational Data

Enclosure:

As stated DISTRIBUTION:

POR V AEOD CF ROAB CF ROAB SF RFreeman WLanning KSeyfrit TIppolito CHeltemes, Jr.

4 R D SC: :AE00 J

BC:ROAB:AE0D DD:W R as WL 1 KVSeyfrit TI M 1 8

8G /85 8/3()85 fly 85 i

w .- - - , . .