The Kalpakkam `incident'

Published : Aug 29, 2003 00:00 IST

The nuclear establishment describes as "serious" the January 21 incident in which six workers of the Kalpakkam Reprocessing Plant were exposed to radiation levels exceeding annually permissible limits, but argues that it was not a case of dangerous exposure.

ON January 21, 2003, six employees of the Kalpakkam Reprocessing Plant (KARP) were exposed to radiation exceeding the annual dosage limit prescribed by the regulatory authorities. In a press conference on August 6, their first since the incident, the authorities of the Bhabha Atomic Research Centre (BARC), which controls KARP, admitted that the incident was a "serious" one. The incident led to the closure of the main plant at KARP, where plutonium is reprocessed, for more than six months and the plant is now scheduled to reopen before the end of August.

While conceding during the press conference that it was the "worst accident" in the Department of Atomic Energy's (DAE) history, BARC Director Dr. B. Bhattacharjee insisted that the incident was a minor one falling between Levels 1 and 2 in the International Nuclear Event Scale. (The scale ranges from 1(anomaly) to 7 (major accident). The Chernobyl disaster was a Level 7 event and the Three Mile Island incident was classified as one of Level 5. Any event between 1 and 4 is categorised as an incident and events above 4 are called accidents.)

Bhattacharjee asserted that "there is no way of classifying it (the KARP incident) as an accident". He blamed the incident on "a little bit of over enthusiasm", an "error in the technical judgment" of the employees, and a failure of equipment that went unnoticed. Bhattacharjee, however, refused to reveal the radiation doses received by the affected personnel, claiming that "it is not proper to disclose them". He admitted that the doses they received had "exceeded the annual [prescribed] dose limit of 20 millisievert" but asserted that they were "much, much lower than the [prescribed] life-time dose limit of one sievert" (1,000 millisievert). He described the six personnel as "cheerful".

The incident took place when a valve separating a high-level radioactive liquid waste tank and a low-level liquid waste tank malfunctioned and started leaking. This resulted in high-level radioactive waste mixing with the low-level waste, which led to an increase in the radioactivity in the low-level tank. Six employees on the night shift, who went to collect samples of the low-level liquid received radiation doses that were higher than the annual permissible limit. There were no monitors to detect the radiation level in the area, which is described as a low-activity area or low-probability zone. The workers were not wearing the personal thermo luminescent dosimeter (TLD) badges either, which register the radiation doses received. Blood samples of the affected personnel, including a woman, were sent to the Biomedical Division of BARC in Mumbai, which assessed that there had been "no clinical damage to their health".

Bhattacharjee blamed the incident on an error of judgement since the six persons were under the impression that they were collecting samples of only a low-level liquid and they did not wear their TLDs. Bhattacharjee also said that since the capacity of the high-level liquid waste tank was three lakh litres, a small decrease in the level in any one section was difficult to notice, especially with analog instruments. The instruments were now being made digital. He maintained that there was no need to reveal the incident (to the press) because it was "an internal issue". Besides, he said, there was no release of any radio activity into the environment and the public had not been harmed. New digital gamma monitors had been installed when presspersons visited the low-level liquid tank area.

The safe limits of radiation doses that nuclear plant personnel and people living outside nuclear plants can receive are prescribed by the Atomic Energy Regulatory Board (AERB), which keeps tabs on safety and radiation issues in nuclear facilities in the country. These facilities work under the DAE. At the international level, limits are prescribed by the International Commission on Radiological Protection (ICRP).

According to the AERB, a nuclear facility worker may receive up to 100 millisievert of radiation over a five-year period with an average of 20 millisievert a year, but the dose should not exceed 30 millisievert in a given year. The ICRP has stipulated the same five-year dosage but it is more liberal in allowing an annual dose limit of up to 50 millisievert. The life-term dose that a nuclear plant worker can receive is one sievert (1,000 millisievert).

Members of the BARC Facilities' Employees Association at KARP are also unwilling to reveal the doses received by the six affected workers. A former office-bearer of the association claimed: "Nobody knows authentically the doses they received." Informed sources, however, said the affected persons received doses ranging from 30 millisievert to 52 millisievert.

Dr. Anil Kakodkar, Chairman, Atomic Energy Commission, and Secretary, DAE, said: "Naturally, we had to go through all safety reviews, which have been done. The main plant was shut down. The affected people are in good health. There is absolutely no question of any radioactivity being released into the environment or affecting people living outside. Things were blown out of proportion."

In a letter to Dr. Bhattacharjee on January 24, 2003, the employees' association said the incident occurred when an employee, Srinivasa Raju, was sent to the Waste Tank Farm to sample a solution whose history was not known. The area had no air monitors. The date of the last survey done there was not known. The letter said: "As soon as the sample was kept in a tray in the process control laboratory, the area gamma monitor started giving visual alarm. The audio alarm was not working... Had there been an area gamma monitor, this whole episode could have been avoided. The plant management is at fault for not ensuring an area gamma monitor in the work place... The Health Physics Division was at fault for not conducting regular surveys at the workplace." All this led to the young employee being exposed to "a very high" dose of 40 millisievert, it alleged. It demanded a full-fledged inquiry into the incident.

The association called for a series of safety measures at KARP, including the appointment of a full-time trained security officer, who will be responsible for planning and executing tests to avoid untoward incidents, the installation of gamma monitors in all workplaces, surveying by the Health Physics Division in all areas, the display of tags indicating the radiation level and the ready availability of TLD readings to the respective area-in-charge. It also suggested that clear instructions be given to employees on what they should do when monitors sound the alarm and wanted facilities to wash one's hands and feet in all access galleries, and the presence of an association representative at local safety committee meetings.

Association members resorted to a work-to-rule agitation in the second week of May, demanding, besides safety measures, promotion for 32 helpers at KARP as tradesmen. The DAE transferred association president R.K. Shenoi and joint secretary Cherian to nuclear facilities at Tarapur and Nashik respectively. A member of the DAE top brass said: "Workers wanted en masse promotion, which is not possible. So they agitated. They are back to work now."

Association members divulged little information on the issue to the press. A former office-bearer declined to talk to this reporter on July 31, saying: "We are not authorised to talk to the press." When asked why the association did not reveal the incident to the press for five months after it took place, he replied: "There is no remedy in talking to the press." He added that the BARC authorities were "responding to whatever (safety measures) we ask for. Still certain incidents (like the one on January 21) take place". Another office-bearer pointed out: "If I talk to you, I can be booked under the Official Secrets Act."

Prime Minister A.B. Vajpayee inaugurated KARP, which is one of the three reprocessing facilities in the country along with Trombay and Tarapore, on September 15, 1998 (Frontline, October 9, 1998). KARP is a radiochemical plant that recovers plutonium and uranium from the spent fuel of the Pressurised Heavy Water Reactors (PHWRs), which are key components of India's nuclear electricity generation programme. The PHWRs use natural uranium as fuel and heavy water as both moderator and coolant. Reprocessing leads to the separation of vast amounts of radioactivity in nitric acid solutions known as high level waste (HLW), which are kept in underground tanks away from the main plant. This underground storage facility is not manned because it is not a regular work area. Persons are engaged to work in this area under special procedures.

Reprocessing of plutonium forms an "important link" between the first stage of India's nuclear electricity programme, which comprises the PHWRs, and the next stage, under which Fast Breeder Reactors (FBRs) will be built. The plutonium recovered from the spent fuel of the existing PHWRs will be used as fresh fuel in the FBRs. A pilot-scale Fast Breeder Test Reactor (FBTR) is already operational at Kalpakkam. The construction of a massive 500 MWe Prototype Fast Breeder Reactor (PFBR) has begun there. Since the DAE plans to build a series of FBRs in the coming years, there was a necessity to establish KARP and start reprocessing plutonium.

KARP was categorised as a "strategic facility" after India's nuclear tests in Pokhran in May 1998. Although plutonium from research reactors is generally used in making atom bombs, it is not difficult to use plutonium reprocessed from power reactors to make nuclear bombs. In April 2000, the DAE decided to keep "the safety and regulatory functions" at BARC, Trombay, out of the purview of the AERB. India's nuclear weapons programme is essentially based at BARC. The satellite facilities under BARC, such as KARP and Rare Materials Project, Mysore, are also beyond the AERB's scope of control. An internal safety committee was set up to oversee regulatory and safety functions at BARC and its satellite facilities.

Dr. V. Pugazhendhi, a medical practitioner who lives close to Kalpakkam township and specialises in the effect of ionising radiation on nuclear workers and nearby residents, says plutonium radiation has a long-term effect because its half-life is 24,000 years.

T. Mohan, general secretary, Atomic Energy Employees' Association, Kalpakkam, said the primary demand of his organisation was that a separate safety officer be appointed for KARP. He also pointed out that helpers, who were not qualified, were sent to collect samples and suggested that frequent classes be held to educate workers on safety aspects. "There is nothing wrong in providing awareness to workers on safety," Mohan said. In all Western countries, nuclear utilities periodically disclose the radiation doses received by workers. Mohan alleged that this was not done in India. He maintained that radiation doses received by nuclear workers should be put up every week in the facilities.

S. Basu, Director, KARP, called it "a rare event" which occurred in "a low probability area". The six persons had been taken out of their work spot in the radiation zone, he said and added that the Operating Plants' Safety Review Committee had made several recommendations to enhance safety and they were being implemented. More radiation monitors were being installed. Additional training was being given to personnel. "The entire staff are given refresher courses," he said. Basu said the plant personnel "understood" the situation and were "cooperative". Their demands on safety were being fully implemented, he said.

In a press release, BARC alleged that the employees' association used the incident as a "respectable safety cover" to settle other disputes and added that the agitation was against "public interest" and "accordingly, was dealt with firmly". After two "instigating" personnel were transferred, others had resumed normal work from June 25, it added.

Dr. V. Venkat Raj, Director, Health, Safety and Environment Group, BARC, said on August 6 that three levels of safety committees had cleared the restarting of the main reprocessing plant. A regulatory inspection team from BARC was to visit KARP in 10 days. A decision would be taken after the team's visit on when to allow the plant to function again.

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