Eigenvalue Trends at BVPS-1 and BVPS-2 - Studsvik...BVPS-1 and BVPS-2 Kenneth Naugle First Energy Nuclear Operating Company A-GO-2 76 S. Main St. Akron, OH 44308 [email protected]

May 2006, CMS Users Group, May 2006, CMS Users Group, Minneapolis, MNMinneapolis, MN 11

Eigenvalue Trends at BVPS-1 and BVPS-2

Kenneth NaugleFirst Energy Nuclear Operating Company

A-GO-276 S. Main St.

Akron, OH [email protected]

May 2006, CMS Users Group, Minneapolis, MN

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Computer Codes

CASMO-4, v2.05.10

CMSLINK, v1.22.00

INTERPIN, v3.03

SIMULATE-3, v6.07.17 (FENOC build)

XIMAGE tool, v2.0.36

May 2006, CMS Users Group, Minneapolis, MN

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BVPS Reactivity Issue

Recent experience with EOC Keff & Critical boron indicates an adverse trend for BVPS-2 (and BVPS-1 to a lesser extent)Increasing excess reactivity towards EOCCurrently ~+300 pcm at BVPS-1 EOC17. BVPS-2 ~+400 pcm MOC12. Project >+500 pcm at EOC12.

May 2006, CMS Users Group, Minneapolis, MN

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History

Both units, calorimetric using Feed Venturi until 2001Switch to LEFM measurement and 1.4% power uprate after 10/2001.Unit 2 did not see a power increase (OE12686) and concluded BVPS-2 was running at ~1.5% overpower prior to 2001.Core model did not confirm overpower condition.

May 2006, CMS Users Group, Minneapolis, MN

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BVPS-1 EOC Critical Boron

• BVPS-1 current trends indicate a relatively steady trend in EOC reactivity as represented by the EOC ΔBoron

• Note 1.4% power uprate (improved calorimetric, Cycle 15)

• There may be a trend from cycle 15 on.

• Current EOC Keff ≈ 0.9970

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• Current data indicates an increasing trend in EOC surplus reactivity at BVPS-2 as represented by the rising EOC ΔBoron

• Note 1.4% power uprate (implementation of improved calorimetric mid-Cycle 9)

• Current EOC Keff ≈ 0.9961

BVPS-2 EOC Critical Boron

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BVPS-1 Cycle K-eff Trends

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BVPS-2 Cycle K-eff Trend

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BV2C12 Eigenvalue Comparison

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Issues

Vendor code agrees with SIMULATE-3 results.System experts have not identified any problem with current calorimetric.The BVPS-2 system is the superior system (Check+ LEFM). BVPS-1 has the older “Check”system.Future power uprates will add additional 7.8% power at both units

May 2006, CMS Users Group, Minneapolis, MN

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BVPS-2 EOC Critical Boron at Constant Power

May 2006, CMS Users Group, Minneapolis, MN

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Conclusions

Current core models show a gradual reduction in critical Keff with increasing core exposure.Concern at BVPS-2 is to avoid Δρ approaching T.S. limit of 1%.BVPS-2 model at constant power is consistent, but Δρ seems high.Future power uprates are a wildcard, effect must be carefully watched.