Ascó managers go
17 April 2008
Changes have been made to the senior management team of the Ascó nuclear power plant, while details of the process of the recent emission of radioactive particles have been released.
The board of Asociación Nuclear Ascó-Vandellòs (Anav) decided yesterday to dismiss Rafael Gasca as head of the Ascó plant and replace him with Cesar Candás who previously headed the Vandellòs plant. In addition, Françesc Gonzalez Tardiu has gone from the role of chief of radiological protection to be replaced by Genís Rubio, who will also head the team researching and analysing how the emission took place and undertaking the program of work prescribed by the Consejo De Seguridad Nuclear (Nuclear Safety Council, CSN).
The changes come after radioactive metal particles escaped from the ventilation system of Ascó 1's nuclear fuel building. Although the particles did not travel far on site, and there is no evidence that they passed the site boundary, the incident become more serious when CSN discovered that Ascó staff had underestimated the total amount of radioactivity released - and did not alert the regulator promptly when they realised the mistake.
The impact of the release was very low in CSN's estimation, and legal radiation dose limits were not exceeded, but the miscommunication between plant operator and safety regulator has caused CSN to rate the incident at Level 2 on the International Nuclear Event Scale. CSN is also considering what 'punitive' measures to take against Anav.
Release process
A summary released by the Spanish Nuclear Industry Forum (Foro Nuclear) and distributed by Foratom has revealed details of the particle release.
During the November 2007 refuelling outage at the Ascó 1 pressurized water reactor, ventilation ducts in the fuel building became contaminated with activated corrosion products which had been collected at the final stage of clean-up of the the fuel transfer canal.
After three days of recirculation through the emergency ventilation and filtration system, the normal ventilation path was restored. This is thought to be the origin of the release, said Foro Nuclear.
On 14 March a particle was found in front of the containment building equipment hatch and further investigations revealed the presence of more particles on the roof of some buildings around the ventilation stack. Ascó staff then had enough information to determine the source of the particles and the cause of original contamination explained above.
Ascó officially notified CSN on 4 April and began a three-day clean up operation of the particles, 95% of which had been deposited close to the point of emission. None had travelled to the more remote parts of the site, or crossed the site boundary. Further deposit sites of particles have since been found and these are now being cleaned up.
Currently Anav and CSN are surveying the plant site and checking the approximately 800 workers that have passed through since November 2007. So far around 600 have been checked and all have proven to be uncontaminated.