Something seems to be going very badly wrong with quality at power plant construction sites, and it is not just confined to OL3, Finland’s infamous nuclear project – at least judging by RWE’s recent experience. In a remarkable presentation at VGB’s Power Plants 2009 conference, Lyon, 23-25 September, RWE’s Dr Manfred Kehr recounted some very troubling quality lapses, in both manufacturing and assembly, that have been happening at the German utility’s fossil construction projects, and he has the pictures to prove it. These included the sorry sight of extensive rework underway on a boiler at Neurath. One problem here appears to have been the challenge of working with T24 (7CrMoVB10-10), a relatively new material, also referred to by another utility speaker at the VGB conference, Martin Giehl of EnBW.
A specific T24 issue encountered by RWE has been cracking at tube/fin joins within membrane walls, due to such factors as lack of post-heat treatment, wrong welding procedures and incorrect assembly sequence. But Dr Kehr’s slides also showed that the problems are not confined just to “exotic” alloys, but also occur in the manufacture of more mundane structures such as boiler steelwork.
Overall, as Dr Kehr’s paper suggests, we seem to be experiencing a gap between what is claimed by some fossil plant vendors and what is being achieved in reality – not an altogether uncommon situation in the power business, as some of those who have purchased advanced large turbines in recent years might testify.
Among the large catalogue of failings recounted by Dr Kehr: non-compliance with basic design criteria and specs; poor QA documents; poor manufacturing, with “relocation of shortcomings in manufacturing to the building site”; lack of manufacturer knowledge about laws pertaining in the country where the plant is being built; “insufficiently qualified and experienced assembly staff”; “large amount of rework on manufactured components”, leading to delay; lack of transfer of experience gained with new materials from manufacturing to the construction site; and “calculated optimism in time scheduling.” And that’s taking just a few of Dr Kehr’s comments, more or less at random.
One particular underlying area of concern is the extensive use of subcontractors, many overseas, and their inadequate supervision (something they know all about at OL3 where a large number of major components have had to be re-manufactured). Dr Kehr said on his projects there were a “confusingly large number of suppliers with small scope of delivery or small volume” and there were sometimes poor communications between the manufacturer and his suppliers. He characterised the risk to RWE of a main contractor using large numbers of sub-contractors (over 100 in the case of a large boiler) not fully evaluated by his company as similar to that posed to a ship by the large mass of an iceberg that lurks unseen below the surface. To reduce risks the requirements that apply to the main contractor must also apply to “the entire chain of subcontractors”, he suggested.
In Dr Kehr’s view, quality problems are the reason why so much European (in particular German) new build is behind schedule (citing Neurath, Lingen, Walsum 10, Uerdingen, Moorburg, Datteln 4, Irsching 4 and 5, Langage, Flamanville 3 and of course OL3 as examples) and are a major contributor to cost escalation, noting that claim management “consumes substantial resources on both sides of the contract” and jeopardises “timetable and economic efficiency.”
While no one would ever suggest that building large power stations at the very cutting edge of technology was ever going to be easy, the issues raised by Dr Kehr demand a response from the vendor community. As he concluded the “problems can only be solved jointly” and require “open communication between all those involved.” We gladly offer Modern Power Systems as a platform for this process.
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