I do not know for the Russian PWR's Bur use different enrichments as they have water gaps for the control rods that give power spikes in particular at the corners

it may effect the size of core and geometry . use of expensive materials like heavy water and graphite may be avoided

Regarding the fuel management in the VVER 1000 core, the following references might be useful: http://vant.kipt.kharkov.ua/ARTICLE/VANT_2013_2/article_2013_2_50.pdf https://inis.iaea.org/collection/NCLCollectionStore/_Public/41/131/41131414.pdf

Thank you Dr. Florian Glodeanu.

The Hungarian NPP Paks was built with four WWER-440 blocks (the most important data can be found in the referred TECDOC). Changing the enrichment of the fuel, and adding Gd as burnable poison,

• the campaign length was increased from 12 to 15 months,
• the burn-up was increased,
• the fast neutron exposure of the vessel was decreased,
• and the power distribution in the core kept flat,
• furthermore the block power was increased from 440 to 500 MW, with 50 years service life instead of the original 30 years.

The task described in the TECDOC was a calculation exercise and did not belong to the realistic problems of NPP operation.

http://www.npp.hu

@ Egon János Szondi

Sir, thanks for your detail response. It would be helpful for me if you please mention who have designed the Hungarian reactor core… engineers from Russia or Hungary? If it is from Hungarian side then who are the personnel, university, R&D organization or some other authority? Actually who solves the realistic NPP problems, vendor, the operating company or some other body hired?

Mohammad Sayem Mahmood

You should address your questions to the NPP Paks:

[email protected]

The specialists are informed on your questions.