Talvivaara Mining ( LON:TALV ) tumbled in early trade after announcing that it will miss its full year nickel production guidance of 25-30,000 tonnes. The company will update guidance for the year in its interim report, which will be released in mid-August. The downgrade is due to operational problems experienced in the second quarter, which included flooding and excessive rain as well as a fatality, which forced a work stoppage. This stoppage continued through the early April, prompting the company to bring forward the scheduled maintenance from May to April to minimise the overall stoppage time.