FW: KKNPP REACTOR PRESSURE WELDS
Hemantha Withanage
From: Padmanabhan Vt <vtpa...@gmail.com>
Date: Mon, Jun 11, 2012 at 7:58 PM
Subject: KKNPP REACTOR PRESSURE WELDS
To: Ramesh Radhakrishnan <cypher...@gmail.com>
Dear friends,
A paper on the welds on the core region of KKNPP reactors is attached. It appears that the pressure vessel is an old version, with unknown risk factors. There are issues of violations of contractby the supplier and collusion by the recipients.
This paper has been submitted for publication in a journal. As such kindly do not publish or quote this. Sorry for being so late. I blame on RTI in India.
________________
The VVER reactor under commissioning at Kudamkulam in Tirunelveli district of Tamil Nadu, India differs from the one featured in the inter-governmental agreement between Russia and India. According to documents published in 2006, there was no weld on the beltline (middle portion) of the reactor pressure vessel (RPV). AERB says that there are two welds on the beltline of the RPV installed at KKNPP.
VVER beltline welds are one of main causes of accelerated ageing of RPV, known as neutron embrittlement, which may damage the vessel and lead to a major accident. Other known cause of accelerated RPV ageing is the impurities and alloying elements in the base metal and weld metal. Beltline welds have been eliminated in the recent versions and the newest RPVs have lower concentration of ageing-elements. This is a breach of the contract by the supplier in Russia. NPCIL officers who knew this were guilty of (a) installing an unsafe machine withhigh risk of RPV failure leading to offsite radiological contamination besides causing financial loss to the company in case of premature retirement of the reactors. By consenting to its erection, AERB also reneged on its responsibilities. Incidentally, according to the existing compensation regime, the supplier has no liability. These legal issues will have to be investigated and decided upon by appropriate national and international agencies.
If the reactor is hot-commissioned, it will be virtually impossible to subject the vessel to a detailed inspection. This will lead to destruction of evidences of the crimes. From a safety perspective, the IAEA mandated study of pressurized thermal shock (PTS) has to be done before commissioning the reactors at Kudankulam.
--
RESIST globalisation COMBAT communalism DEFEND democracy
http://insafindia.org/?page_id=2 (insaf publications)