Penalty for Ascó emission

Tuesday, 15 April 2008

A small amount of radioactive metal particles were released at Spain's Ascó nuclear power plant on 4 April. The incident has been classified at Level 2 on the International Nuclear Event Scale scale by the country's nuclear regulator, which was dissatisfied with the information it received.

 

Ascó

The particles escaped from the nuclear fuel building of Ascó's first pressurized water reactor unit through ventilation ducts and were detected by nearby monitors on 4 April, said the Asociatión Nuclear Ascó - Vandellòs (Anav), which operates the Ascó and Vandellos II nuclear power plants for owners Iberdrola and Endesa.

 

The company notified the Consejo De Seguridad Nuclear (Nuclear Safety Council, CSN) the same day and began a three-day clean-up operation which confirmed that the particles had not travelled to the more remote areas of the plant site, such as cooling towers, the administration building or the Ebre River. Anav said that '95% of the particles were deposited close to the point of emission'. CSN investigators began their own investigation at the Ascó site on 5 April, concluding two days later.

 

'Inappropriate material control'

 

Anav said that a study into the root cause of the incident and its sequence of events have now been concluded. Results of laboratory measurements released today indicate that the total activity of the discharged particles was 0.0023 curies (84.95 MBq).

 

However, this figure differs from the estimate initially reported to CSN, which has decided to raise its rating of the incident from level 1 to level 2 on the International Nuclear Events Sace (INES).

 

CSN said today this was due to Anav's 'inappropriate material control and providing incomplete and inadequate information', asserting that Anav knew from 9 April that the information it had given to CSN and the local community around Ascó had been incorrect. The safety body is now considering imposing penalties on Anav.

 

In terms of impact, the emission has been insignificant. CSN said the radiological impact of the release 'remains very low' and is below legal dose limits for plant workers, while there was no effect off site. To verify this Anav is measuring the dose received by everyone that has passed through the Ascó site since 28 November - some 700-800 people. So far, 579 people have been tested and there has been 'no evidence in any case of incorporation of radioactive material'.

 

CSN's president, Carmen Ten Martinez, is to give evidence on the affair to the Congress of Deputies, Spain's lower house.

 

Further particle find

 

A CSN statement released late on 16 April has revealed that more radioactive particles have been detected as a result of the monitoring program carried out by Anav and overseen by CSN. The new particles were found in the same areas as the others, and their level of activation is being evaulated. CSN said the monitoring program would continue until it could rule out the presence of any more particles.

 

The regulator also said it would begin a surveillance campaign on 17 April, checking for radiation at the exterior of the Ascó site. It said this detailed work would be complimentary to that it carried out on 5 April. Anav's checks of site personnel are to be independently audited by the Dirección Técnica de Protección Radiológica (Technical Directorate on Radiological Protection, DPR).

 

To explain this entire sequence of events to local residents, CSN has decided to hold a briefing with the mayors of nearby areas on 22 April. These moves were the result of a special CSN plenary meeting on 15 April.