P N Krishnamoorthy : a pioneer in radiological protection, an outstanding scientist and an able administrator

Dr K.S.Parthasarathy
Raja Ramanna Fellow, Department of Atomic Energy

In the passing away of Shri.P.N.Krishnamoorthy, popularly known as “PNK” on November 16 this year, the country lost a pioneer in radiological protection, an outstanding scientist and an able administrator. Largely by his efforts and Dr Homi Bhabha’s support he could establish a robust safety frame work to initiate steps to enforce radiological safety requirements nation wide in institutions using radiation sources for medical, industrial, agricultural and research, many years before the Central Government set up the Atomic Energy Regulatory Board, a dedicated body to enforce safety provisions under the relevant Sections of the Atomic Energy Act 1962 (33 of 1962).

Shri P N Krishnamoorthy ( 1927-2009)

Early years

PNK was born on 12 th July 1927 to (Late) Sri P.K.Nilakantan & (Late) Smt Alamelu. Shri Nilakantan worked as Accounts Officer in the office of the Accountant General in Rangoon when the war broke out. He came back to India in 1942 in the thick of the war and was posted in Allahabad till 1945.
He returned to Rangoon after the war, but came back to India in 1949 after Burma got Independence. He worked in the Central Tractor Organisation till 1955, when he joined Damodar Valley Corporation (DVC) in Bokaro and then Durgapur and retired in 1962.
PNK had his initial education in Rangoon in B.E.T. High School. His father was a great musician and music lover. At the tender age of seven, PNK started learning music under him. PNK won awards in many competitions in Bharatiyar music and classical Carnatic Music. He also acted as Naradar (singing and acting) in many dramas; Shri. Chari, the prinipal of B E T School, was all praise for his acting talents.

PNK was to have appeared in the SSLC in 1942, when the family came by the last ship to Madras. The SSLC exam was in April. The erstwhile Madras SSLC Board gave him special permission to appear for the exam; he came out with flying colours. He joined Government Victoria College, Palghat and did his B.Sc. He was fairly good at playing Tennis and was a keen dramatist.
In 1947, he joined Wilson College, Bombay. During his post graduate programme, he came into contact with Prof. H.J.Taylor; Prof. Taylor was also a keen Tennis player.

Work at TIFR
Dr Homi Bhabha had set up the Tata Institute of Fundamental Research (TIFR) in June 1945. Immediately, he organized experimental cosmic ray research under three different groups. Professor Taylor who was professor of physics in Wilson college simultaneously led the nuclear emulsion group; A.S.Rao and A.B.Sahiar led the high altitude study group and the cloud chamber group respectively (B.V.Sreekantan, Current Science, 10 Dec, 1991).
According to Professor R. R. Daniel, the research group consisted of fresh M.Scs in their twenties with one to three years of introduction to research (Current Science, 10 Dec, 1991). PNK joined TIFR initially as a research student and later continued as a research assistant.
He actively participated in the balloon launching experiments. In a typical launch, they used 32 balloons filled with hydrogen and attached to a 400 feet line to lift 40 kg of equipment to heights of 40,000 to 94,555 feet. Fascinated by these efforts, Professor Bernard Peters, eminent cosmic ray physicist from the University of Rochester came to TIFR for the first time in 1950 and later accepted the invitation of Dr Bhabha to stay back till 1957. He set up a group carrying out outstanding research in one of the most exciting fields.
PNK co-authored a paper titled “High Altitude Balloon Experiments and Measurement of the Heavy Primary Radiation Flux at the Geomagnetic Equator” (Proceedings of the Indian Academy of Sciences, July 1952) with H J Taylor and M.Sitaramaswami. Using stacks of nuclear emulsions and other simple and elegant experimental set up, they measured the heavy primary radiation flux at the equator. The team carried out the study directly under the guidance of Prof. Peters.
The list of persons working in the field as given at the end of PNK’s paper included R. R. Daniel, D.Lal, K.G.Vohra, Yash Pal among others.
Nuclear emulsion was the most important medium used for recording cosmic ray particles. Shrinkage of nuclear emulsion adversely affected cosmic ray studies. PNK ingeniously solved the problem by replacing silver halide in the emulsion during the fixing stage, by adding Canada balsam (Proceedings of the Indian Academy of Sciences, May 1957). Professor Peters communicated the paper to the journal. PNK thus had the opportunity to work with some of the finest brains in the world.
Tryst with radiological protection.
Shortly, he shifted away from cosmic ray work. Loss of cosmic ray study group was a gain for the then newly emerging field of radiological protection!
In 1959, A S Rao, a close associate of Dr Bhabha, asked PNK to take over the Radiological Measurements Laboratory (RML). Rao set up RML to provide radiological protection services to institutions outside the Department of Atomic Energy (DAE).
That was a watershed in PNK’s career. The use of radioisotopes in medicine, industry, agriculture and research was increasing rapidly. RML provided personnel dose monitoring services, surveyed medical x-ray units and started developing radiation measuring instruments. The extracts from the annual reports of DAE from 1959-1964 indicate the rapid progress made in the field of radiological protection. (Old timers may see typical drafting skills of PNK!)

Annual report 1959-60

Annual report 1960-61 (RML changed into RMS during this period)

The initiation of gonad dose measurements nation wide, is explained thus:

We can see the beginning of R & D in making radiation measuring instruments in the following:

Not many may know that RMS, under PNK, contributed to the amendment of the Atomic Energy Act 1948. Please see the following extracts from the Annual report of DAE 1960-61:

The beginning of various training programmes is referred to in the DAE Annual report of 1960-61:

DAE Annual reports appear to have undergone some drastic pruning. The report for the year 1960-61 had 73 pages; the Annual report of 1961-62 had only 17 pages. The RMS report was just one para. The assistance to Burma started.

During 1962-63, nothing remarkable took place except that the service component of RMS increased. The report of Film Badge Service etc appears under Health Physics Division. During 1961-1963, PNK was abroad serving the International Atomic Energy Agency (Please see under Service abroad with the IAEA).
Extracts of Annual Report of 1963-64: (DRP set up. First one year post-graduate training concluded)

From 1959 to 1972, PNK implemented with evangelic zeal a nation-wide, radiological protection programme. In 1970, the International Radiation Protection Association invited him to deliver a talk on “Radiological Protection Problems in the Developing Countries” (Health Physics, August 1971) at its Second International Congress at Brighton, England.

I was then studying for my PhD (medical physics)  at the University of Leeds, UK, as a Colombo plan study fellow at the erstwhile MRC Environmental Radiation Research Unit and the Department of Medical Physics, The General Infirmary, Leeds. I attended the IRPA Brighton conference as a delegate from UK

At 43 , PNK was among the handful of the youngest radiation protection specialists to address the meeting. His speech must be made compulsory reading material for all budding radiation protection professionals.
With his customary eloquence and clarity of thought, he listed the daunting difficulties faced by developing countries in implementing an effective radiological protection programme. The audience listened to his memorable talk with rapt attention when he listed the problems faced by developing countries and the solutions

He highlighted many issues.
“…in developing countries, the principal radiation source is….the diagnostic x-ray machine. It is also the principal source of radiation hazard to the doctor, and to the technician; and thanks very often to the dilapidated state of the machine and to the well below par work practices adopted, to the patients as well”, he added.
He pointed out that another source of radiation hazard is the use of radium needles and tubes in cancer therapy. Inadequate storage and handling facilities, employment of relatively outmoded techniques both for preparation and for the application of these sources lead to excessive exposures.
He listed the difficulties observed in industrial and research applications of radiation.
“ The relatively bleak picture that has been painted….is fortunately only the initial phase that one is confronted with, in the implementation of a countrywide radiation safety programme; for, it has been our experience that a radiation protection survey of any installation by a qualified team of experts , which is followed by appropriate advice to the radiation workers in the installation of safe work practices, almost always results in a dramatic fall in the average radiation doses to the workers”, he assured the audience, quoting quantitative data on doses to workers.
His insight on the state of mind and the attitude of young persons joining the profession and the need to fruitfully employ them was evident while he stated thus:
“…..when a large number of capable young men and women with good basic science or engineering degrees are brought together in a service organization of this type, it is inevitable that they should yearn for a part of their time and efforts to be alloted for research. For a radiation protection programme to maintain its basic vitality of approach, it is imperative that in the equilibrium state, about 60% to 70% of the effort should be routine, about 20% developmental and the rest research”. Often, I get a feeling that lately, radiation protection specialists are moving away from this time-tested scheme.
PNK ensured that his staff set apart some time for R & D, in spite of an enormous load of service responsibility
The approach advocated by PNK and followed by his successors helped in establishing, proactive, dynamic and successful R & D efforts which made priceless contributions to the programme. An excellent instance is the development of a totally indigenous calcium sulphate based, dysprosium activated thermoluminiscent dosimeter which replaced film badges in the field of personnel dose monitoring. The TLD group achieved enviable progress and was one of the finest and most advanced R & D programme for a developing country. It may very well be an example for developed nations.
The therapy- dose monitoring programme based on TLD continues to help accurate delivery of radiation doses to cancer patients nation wide. The battery powered, secondary standard dosimeter (Farmer type) is another example-some of them still reported to be functioning satisfactorily.
Other items referred to by him included the need for developing primary and secondary standards, radiation measuring instruments and availability of trained medical physicists cum radiological safety officers.
At the end of his speech at Brighton, he gave a satisfactory answer to a vexing question. Though the Atomic Energy Act was promulgated in 1962, Radiation Protection Rules 1971, the first subordinate legislation was issued only in 1971.
“ This is because, we have found that the promulgation of rules and regulations in respect of radiation protection should be preceded by vigorous measures of the type, I have outlined…” he suggested.
“ The countrywide radiation protection programme, particularly in a developing country, should in my opinion, never start off with the promulgation of rules and regulations in respect of radiation protection.On the contrary, adequate expertise and instrumentation backed up by realistic field training measures should be developed in the first instance to effectively implement a radiation protection programme”, he asserted.
He listed various elements to be readily available for effective regulatory control of radiation sources.
When Dr Homi Bhabha set up the Directorate of Radiation Protection (DRP) in 1963 to provide an effective radiation protection programme nationwide, PNK was the natural choice to lead the mission. A.S.Rao gave him free hand. PNK applied his administrative acumen and organizational skill to establish the programme which thrived under his leadership.

DRP diligently provided personnel dose monitoring services, developed procedures to approve site plans and to license users of radiation sources and equipment, prepared safety standards and organized training programmes. The Radiation Protection Rules 1971 drafted by his team was the first piece of subordinate legislation under the Atomic Energy Act 1962. It reigned supreme till it was replaced by Atomic Energy (Radiation Protection) Rules, 2004.

The one year post graduate training course in radiological physics which, the erstwhile Atomic Energy Establishment Trombay (AEET) started got recognition from University of Bombay. It offered the Diploma in Radiological Physics (Dip R.P.) PNK was instrumental in successfully establishing medical physics as an essential and well respected discipline in the country by stipulating the legal requirement that hospitals handling radiation sources for radiation therapy must appoint a qualified Radiological Safety Officers (RSO) cum Medical physicists.

With the support from the WHO, PNK could get many eminent visiting scientists (Hanson Blatz, Ritchie, James Turner, Larry Lanzl, Swindon among others) to deliver lectures at the one year postgraduate training programme.Some of the trainees performed remarkably well and occupy positions of distinction abroad.
“The one quality of PNK, was the enormous preparation he put into any job he was doing”, Dr G Venkataraman who worked with him closely from 1958 to 1973 remembered.

“PNK laid the foundation for radiological protection in India”, Dr. U.Madhwanath another long term associate said. Under various programmes, PNK sent about thirty persons to hospitals in UK, Canada, Australia, Sweden etc. for training. They formed a core group of teachers for the one year training course in radiological physics and short term training programmes for radiation workers in industries, hospitals and other institutions.

Service abroad with IAEA

While serving the International Atomic Energy Agency (IAEA), as a consultant, PNK co-authored the Health Physics Addendum (July 1960) with Mr G J Appleton of the United Kingdom Atomic Energy Authority. This was the first Addendum to the Manual on Safe Handling of Radioisotopes, the first operational safety standard of the IAEA and was meant for small scale users of radiation sources.

During 1961 to 1963, PNK served the IAEA as Senior Officer (P5 grade) in the Division of Health Safety and waste Disposal. He was actively involved in organizing and providing technical advice worldwide on research and development programmes in health physics and radiation safety.

He served as Consultant to the legal Division of the Agency. He was associated with the studies on the radiation hazards of space travel and worldwide waste management issues.He represented the Agency on many international meeting on these subjects.

Besides these, he served IAEA, World Health Organization (WHO) and International Labour Organization ( ILO) as a Consultant on radiation safety and associated problems. He delivered lectures at many international training courses on the legal aspects of atomic energy. He attended nearly 60 international symposia and panels as an invited expert.

He was designated Alternate Governor from India to the IAEA.He repesented India on the Board of Governors of the IAEA in 20 meetings in this capacity. He went on technical assistance missions for international organizations on many occasions to various countries.

PNK , the wordsmith

In 1954, Dr. Homi Bhabha wrote a one page “summary note” to Pandit Nehru on his vision on atomic power generation. Brief and to the point, Bhabha’s letters reflect his clarity of thought. A handful of people in the Department of Atomic Energy acquired the drafting skill of their mentor. PNK was undoubtedly one of them.
PNK set up a “Cell” to collect, collate and preserve information relevant to the atomic energy programme. He informally chose a few young scientists with aptitude to learn, to man the “Cell”.They included A.N Nandakumar, V. N Neelavathy, T S Subramanian, R B Vora among others. PNK equipped the “Cell” with modern electronic gadgets (electronic printers, copiers, slide projectors etc.). He loved them.
“Cell” inmates could produce conscise reports on any topic at short notice. The rough drafts they prepared underwent rigourous editing, review and critical appraisal by PNK, who was the pricipal ‘wordsmith’! He used his scissors mercilessly, chipped, chiselled and sharpened the text. Often, they were briefs for Dr Vikram Sarabhai, Chairman, Atomic Energy Commission. That the material originated from the “Cell” was not a State secret! Probably not many knew that from 1967 to 1972, Dr Sarabhai appointed PNK as Staff Consultant, Atomic Energy Commission.We were benefited by our association with the Cell. Some of us turned into wordsmiths!
In addition to the work as Deputy Director, DRP, PNK was associated during 1964-66, with Dr Homi Bhabha in the work of the Scientific Advisory Committee to the Cabinet of which Dr. Bhabha was the Chairman. During most of 1957 to 1973, PNK was closely associated with the Department of Atomic Energy, on the legal, international and technical aspects of its work. He assisted DAE in drafting many international cooperation agreements and international legal treaties in the field of atomic energy

Service to Department of Electronics
Shortly, PNK went to the Department of Electronics as Director (Technical).He dealt with problems connected with manpower development in the field of electronics in the country. He was associated with the upgrading of existing training programmes ,and the setting up of a number of new electronics training programmes including the formulation of syllabi and setting up of the laboratories and other facilities for such programmes. He was responsible for external relations in the field of electronics and negotiated many agreements for cooperation and commercial /technical collaboration in the field of electronics with many countries.
Service as Controller , BARC
Later, he returned to BARC as its Controller. He introduced several long lasting administrative measures in BARC, revamped the way various transactions are formally carried out. He introduced computer friendly, application forms in different colours and centralized the filing system wherever appropriate. His dedicated efforts led to the improvement in the accountability of personnel at different levels. He implemented new procedures to improve the alertness of security personnel.

Contributions to AERB

During the early 70s, there was a proposal to set up an independent Atomic Energy Control Board, the predecessor of the Atomic Energy Regulatory Board. Sadly, this was shelved because of frailties in interpersonal relations. It got delayed by over a decade.

Homi Sethna who followed Dr Sarabhai as his successor,  did not endorse an important decision taken by Dr. Vikram Sarabhai. In 1963, Bhabha established the Directorate of Radiation Protection (DRP) in BARC to enforce radiation safety provisions in non-DAE Units. In 1971, as decided by Sarabhai, DRP was constituted as a separate constituent unit of the DAE. He wanted to set it up as Directorate of Health and Safety under an Atomic Energy Regulatory Authority (AERA). But, Sarabhai died before AERA was set up. Sethna brought DRP back to BARC. Interestingly, in 1981, a committee set up by Sethna recommended constitution of theAtomic Energy Regulatory Board (AERB), if necessary, by amending the Atomic Energy Act (1962), to make it a statutory organization. In November 1983, 12 years after the initial decision, Raja Ramanna implemented the committee’s decision and set up AERB as a separate agency.

Finally when Central Government set up the Atomic Energy Regulatory Board in 1983, thanks to PNK’s deep personal commitment and endeavours, there existed a fairly well organized safety frame work in the form of DRP to enforce safety requirements in radiation installations outside the Department of Atomic Energy and more importantly, he himself joined the Board as its Member Secretary. He brought the first batch of officers who formed the core group to jumpstart the regulatory activities of AERB.

“He served the Board with distinction during its formative years and contributed significantly in establishing robust and well laid out procedures to assist the nascent organization in to an effective regulatory body”. Shri S K Sharma, Chairman,AERB acknowledged in a condolence message.

“He liberally contributed his vast knowledge borne out of decades of experience, for the benefit of the Board as its Member Secretary” he added.

PNK, the connoisseur of music

After his retirement in July 1987, PNK spent his entire life promoting music, which according to many, was his first love. He was Director of the Sangeetha Vidyalaya of Shanmukhanada Sabha since November 2002. He was Honorary Editor of Shanmukha, the quarterly magazine of the Sabha

“He lead a spartan life, devoted his entire retired life to his first love: i.e Carnatic Music, its propagation among the interested masses by giving free lessons at the door step of his students. He used to travel all over the place by even public transport through out the year with great punctuality whether it was rain or shine”, Shri T.K.Sankaranarayanan, along term associate of PNK reminded the participants of a well attended condolence meeting organised by the Bhakta Rasika Ranjini Sabha, Anushaktinagar . He was the heart and soul of the Bhakta Rasika Ranjini Sabha, Anushaktinagar.
The Sabha invited me to talk on PNK’s scientific contributions particularly to the field or radiation protection. I could sense the deeply felt sentiments and respect to the departed soul. The overpowering sentiments of his disciples may be seen if you access the following URL


For many decades, he wrote critical reviews of Carnatic and Hindustani music and dance programmes for The Indian Express. He reviewed nearly a thousand concerts and several hundred dance performances. He wrote two hundred articles on music in the Sunday edition of The Economic Times. For many years, he was a member of the “Sur Singar Samsad Peeth” and served its Senate as vice chairman. He served All India Radio (AIR) as a Judge for selecting musicians for AIR awards, a member of jury for the classification of Carnatic musicians, and as a member of the southern panel of the Music Audition.
PNK’s personal qualities
PNK seldom showed pessimism. During several decades of close association with him only once I noticed that he was overpowered by grief and struggled to control his emotions. That was on January 24, 1966 when he heard of the tragic death of Dr.Bhabha. He had excellent rapport with Bhabha.
Next day the entire staff of AEET assembled before the nearly finished Modular Laboratories to pay homage to the departed leader. PNK read the condolence message. I still remember his emotional, tremulous voice solemnly articulating the sorrow and helplessness of all the participants. It touched everyone.
After the formation of DRP, Bhabha approved large scale recruitment for the organization. At one time, DRP had nearly 50 young officers in SO(A) grade. Because of paucity of space, we worked in two shifts. PNK worked in both shifts, 8.30 AM to 8 PM every day!
Some of us had our seats in a sort of Mezzanine floor close to the asbestos roof in the Electronic shed. It was unbearably hot. Every one complained. During the idle hours, I borrowed a thermometer from the Standardization Group, measured the temperature and plotted it against time to produce a telling graph. The temperature slowly increased from the morning. From 11 AM to 5 PM, it remained steady often above 38 degree celsius! PNK saw it during one of his rounds. I waited with bated breath not knowing how he will react to my “un official” experiment. He appreciated it and showed the graph to A S Rao. The roof got an intermittent water spray from the very next week, a measure which did not offer much relief!
On November 23 this year Dr. Y S Mayya, Head, Radiological Physics and Advisory Division, BARC organised a condolence meeting to pay tributes to the memory of PNK. Dr G. Venkataraman, Dr P. S. Nagarajan, Shri P. S.Viswanathan, Dr. A. S Pradhan and Dr K.S.Parthasarathy
PNK was among the handful of surviving stalwarts mentored by Homi Bhabha. His departure signifies the end of an era.


About ksparthasarathy

I am a former Secretary of the Atomic Energy Regulatory Board. I am a former Raja Ramanna Fellow in the Department of Atomic Energy. Free lance journalism is my hobby
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2 Responses to P N Krishnamoorthy : a pioneer in radiological protection, an outstanding scientist and an able administrator

  1. AMARJIT S MADAN says:

    I am deeply grievedto hear the sad demise of Shri P N Krishnamoorthyof D R P B A R C Trombay MUMBAI. I had worked under his leadership in the Film Badge Servicewhen the name wasR M L and laterD R P since1960/NOV to1972/april.He had a wnderful personality very knowlegeableand a great leadership. When I saw his picture tears rolled in my eyes..My heartfelt codolences to his family and all concerned .A S MADAN NEW YORK May 21 2014..


  2. Sunil Kumar Bhattacharjya says:

    Today a friend sent me the link <Talk by Kavita Krishnamurthy
    , where Kavita Krishnamurthy (KK) talked about her career in music. In that KK mentioned about her parents and that dispelled my earlier thinking that KK could be the daughter of PNK. Then I looked up “PNK” in “Google-search” and found this article in your blog. . PNK was indeed a great man with an imposing personality. I admired him most from the day I completed the course in the AEET Training School and joined his division in July 1964 . The period from late 1965 to early 1966, was difficult in my personal life and I gave the notice of resignation to BARC. Then miraculously, by the grace of God, I met my would-be-wife and I withdrew the resignation. I married on Sept.6, 1966. The next day (i.e. on Sept.7, 1966) BARC accepted my resignation saying that the withdrawal of the resignation was not acceded to. It was a shock to me that my most admired person PNK took a step, without his even talking or discussing with me. I appealed to BARC and three months later (i.e. in Dec. 1966) BARC did invite me to rejoin, but by that time I made my alternative arrangements. The events in Sept.1966, did not diminish my admiration for PNK and in 1977 when I visited BARC on official work, I met my ex-colleagues Kamala Gopekumar, Jashbir Singh and Gouri . I also met PNK, who became the Controller of BARC by that time, to pay my respects, and he was nice to me. I pray to the Almighty that his soul rests in peace.


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