HC Deb 18 April 1990 vol 170 cc938-45W
Mr. McFall

To ask the Secretary of State for Defence at what frequency individual dosimeters of refit workers are calibrated and checked.

Mr. Neubert

[holding answer 4 April 1990]: In accordance with IRR85, thermoluminescent dosimeters are calibrated on receipt and re-calibrated at regular intervals, at least every 50 read cycles, by the defence radiological protective service, a dosimetry service approved by the Health and Safety Executive. In addition, the absorbtion rate of these dosimeters is checked every month. Direct reading dosimeters are tested at least once every 14 months, also in accordance with IRR85.

Mr. McFall

To ask the Secretary of State for Defence at what level and individual radiation dose exposure his Department initiates investigation of the cause of these dose exposures.

Mr. Neubert

[holding reply 4 April 1990]: Investigations are carried out in accordance with the Ionising Radiation Regulations 1985.

Mr. McFall

To ask the Secretary of State for Defence (1) how alpha radiation is monitored to and within specific human organs on individual refit workers; and what account is taken of radium daughter products occurring naturally;

(2) what is the individual lung dose for submariners and refit workers arising from absorption of tritium;

(3) what is the internal organ dose arising from absorption of the radionuclide cobalt-60;

(4) what is the internal organ dose arising from absorption of the radionuclides strontium-90, caesium-137, carbon-14 and the isotopes of plutonium and uranium.

Mr. Neubert

[holding answer 4 April 1990]: The results of routine monitoring of levels of the contamination in the working environment and where applicable, biological monitoring of personnel, confirm that there is no requirement to record radiation doses for submariners or workers at the royal dockyards arising from intakes of radioactive material. In the unlikely event of an accident or incident occurring in the workplace leading to any suspicion of intake of radioactive material, special monitoring of the individual concerned would be undertaken.

Mr. McFall

To ask the Secretary of State for Defence how many claims for compensation have been received from refit workers for radiation-induced illness; how many of these claims have been settled; and how many remain in dispute or progress.

Mr. Neubert

[holding answer 4 April 1990]: My Department has received a number of claims over the years from service and civilian employees for radiation-related illness, but it is not possible to identify, without disproportionate cost and effort, claimants who were engaged on refit work. Every claim received by the Department is dealt with on the basis of legal liability.

Mr. McFall

To ask the Secretary of State for Defence how many of those refit workers subject to radiation doses in excess of 50 milliSieverts in a particular year received the greater part of such doses as a result of some incident or accident outside the range of normal refit operations; if he will describe such incidents; and what conclusions he has reached as to why such abnormal exposures occurred.

Mr. Neubert

[holding answer 4 April 1990]: In the period 1979–89, only one employee engaged on refit work has recorded as receiving an annual dose above 50 milliSieverts, which could not be sensibly attributed to

Annex A
Annual individual radiation exposure for workers at the Royal Dockyards
Year Numbers of workers in dose ranges
0 to 15 mSv 15 to 20 mSv 20 to 30 mSv 30 to 40 mSv 40 to 50 mSv Over 50 mSv
1989 1,306 29 31 5 1 0
(2,763)
1988 1,469 18 10 0 0 0
(2,862)
1987 1,781 19 5 2 0 0
(2,891)
1986 2,115 53 39 5 0 0
(2,560)
1985 2,093 76 62 17 0 0
(2,419)
1984 1,869 111 138 52 8 1
(2,190)
1983 2,090 75 86 36 29 0
(2,518)
1982 2,165 85 69 14 6 0
(2,672)
1981 1,997 93 133 45 11 0
(2,566)
1980 1,784 85 154 89 48 1
(2,877)
1979 1,469 102 125 75 66 2
(1,697)

Mr. McFall

To ask the Secretary of State for Defence if he will list the dates when his Department's radiological protection measures and guidelines for submariners and refit workers were changed, altered or modified.

exposure arising from normal refit operations. The majority of his total assessed radiation dose of 88.10 milliSieverts arose from a single dose assessment of 83.75 milliSieverts from a dosimeter issued for use by that employee in June 1984. A local investigation concluded that the dosimeter had been exposed in the absence of the employee. Nevertheless, the recorded over-exposure was notified to the Health and Safety Executive and the assessed radiation dose remains on the record. Data for years earlier than 1979 are not readily available and could be provided only at disproportionate cost.

Mr. McFall

To ask the Secretary of State for Defence if he will give a breakdown of annual individual radiation exposure for refit workers in the bands 0 to 10, greater than 10 to 20, greater than 20 to 30, greater than 30 to 40, and greater than 50 milliSieverts, for all years since the onset of the naval nuclear propulsion programme.

Mr. Neubert

[holding answer 4 April 1990]: A breakdown of annual individual radiation dose for workers at the royal dockyards for each of the years 1979–89 is given in the following table. The figures shown in brackets are the number of additional employees monitored for exposure to ionising radiations by the local issue of direct reading dosimeters while employed under a written system of work. A more detailed or alternative breakdown of the figures and data for years earlier than 1979 can be produced only at disproportionate cost.

Mr. Neubert

[holding answer 4 April 1990]: Within the Royal Naval submarine flotilla, detailed radiological protection instructions and training and qualification standards are promulgated in classified books of reference which are subject to regular update. The detailed instructions were subject to complete reissue in 1985, following publication of the Ionising Radiations Regulations (IRR85), and have been subject to minor amendments since that time. In addition to these specific instructions, nuclear submariners must also comply with general joint services instructions, which are also updated regularly in line with the promulgation of relevant national approved codes of practice.

Within the royal dockyards, radiological protection aspects are covered by site-specific instructions and standing orders which are produced by the companies and are subject to statutory control. Where relevant, the specific MOD instructions are also compiled with by the contractor in accordance with the terms of the contract.

Mr. McFall

To ask the Secretary of State for Defence if he will provide a definition of those personnel who are generally classed as refit workers who are involved in naval nuclear propulsion plant facilities and who are engaged on or involved with radioactive materials or radioactive processes.

Mr. Neubert

[holding answer 4 April 1990]: The term "refit worker" is not a designation used by either MOD or its contractors. All personnel within the royal dockyards, who require access to controlled radiation areas as a result of their employment, are regarded as being occupationally exposed to radiation. It is in regard to this group that the radiation dose statistics are provided in answering the hon. Member's several other questions.

Mr. McFall

To ask the Secretary of State for Defence if in cases where refit personnel are subject to extraordinary radiation doses, such as in excess of 15 milliSieverts in a particular year, largely as a result of some incident or accident outside the range of normal refit operation, he will publish details of such incidents or cause them to be published in the Health and Safety Executive quarterly statement of nuclear incidents; and if he will make a statement.

Mr. Neubert

[holding answer 4 April 1990]: All exposures of 15 milliSieverts or more within any calendar year are subject to investigation in accordance with regulation 28(1) and (2) of the Ionising Radiations Regulations, with the objectives of triggering procedures to ensure that exposures are being kept as low as reasonably practicable. If an exposure greater than 30mSv in any calendar year occurs, the Health and Safety Executive is notified as required by regulations 13(f) of IRR 85.

Mr. McFall

To ask the Secretary of State for Defence what are the gross numbers of refit workers employed in the United Kingdom, in terms of years employed at each respective port or refit dockyard facilities.

Mr. Neubert

[holding answer 4 April 1990]: The data are not readily available and could be provided only at disproportionate cost. The numbers of employees occupationally exposed to radiation at each royal dockyard since 1979 are shown in the table.

Year Chatham Devonport Rosyth Total
1989 9 2,394 1732 4,13[...]
1988 10 2,677 1,672 4,359
1987 12 2,669 2,017 4,698
1986 17 3,035 1,720 4,772
Year Chatham Devonport Rosyth Total
1985 19 2,936 1,712 4,667
1984 22 3,074 1,273 4,369
1983 447 3,016 1,371 4,834
1982 1,246 2,547 1,218 5,011
1981 1,456 2,159 1,230 4,845
1980 1,915 1,643 1,480 5,038
1979 1,008 1,265 1,263 3,536

Mr. McFall

To ask the Secretary of State for Defence what in-house radiological protection measures and guidelines are adopted for submariners and refit workers; and if these are in addition or supplementary to Ionising Radiations Regulations.

Mr. Neubert

[holding answer 4 April 1990]: Within MOD, radiation exposures continue to be authorised only on the basis that they are justified, comply with statutory limits, and are as low as reasonably practicable (ALARP). Individual measures taken are often site-specific and, in the case of the royal dockyards, are the responsibility of the contractors, who are subject to the legislative requirements.

Mr. McFall

To ask the Secretary of State for Defence what is the accuracy of dosimeters worn by refit workers in terms of percentage of the recorded radiation dose.

Mr. Neubert

[holding answer 4 April 1990]: The accuracy of the personal dosimeters worn by workers monitored for exposure to ionising radiation by the defence radiological protection service meets the criteria specified by the Health and Safety Executive in its "Guidance on the Approval of Dosimetry Services" under the Ionising Radiations Regulations 1985, part 1— external radiations.

Mr. McFall

To ask the Secretary of State for Defence what is the average individual radiation dose, whole body equivalent, for all refit workers involved or who have been involved in the naval nuclear propulsion programme and associated facilities.

Mr. Neubert

[holding answer 4 April 1990]: The average annual radiation doses to workers at the royal dockyards for each of the years 1979 to 1989 inclusive are shown in the following table. Data for years after 1986 have been included with the permission of the dockyard contractors. The data include doses to individuals working under a written system of work who were issued with direct reading dosimeters. Figures for years before 1979 are not readily available and could be provided only at disproportionate cost.

Average annual radiation doses of refit workers
Year Average annual dose (mSv)
1989 1.69
1988 1.26
1987 1.46
1986 1.82
1985 2.47
1984 3.82
1983 2.84
1982 2.34
1981 3.15
1980 3.60
1979 4.91

Mr. McFall

To ask the Secretary of State for Defence what is the distribution of total radiation exposure for refit workers in the ranges 0 to 5, greater than 5 to 10, greater than 10 to 15, greater than 15 to 20, greater than 20 to 25, greater than 25 to 30, greater than 30 to 35, greater than 35 to 40, greater than 40 to 45, greater than 45 to 50 and greater than 50 milliSieverts in terms of percentage of overall work force.

Mr. Neubert

[holding answer 4 April 1990]: The distribution of total radiation exposures of those workers at the royal dockyards who have radiation dose records maintained on computer by the defence radiological protection service, is given in the table. A more detailed breakdown for employees ceasing radiation work before the date on which computerised record keeping was introduced is not readily available and could be provided only at disproportionate cost.

Lifetime dose (milliSieverts) Numbers Percentage
0 to 5 2,318 35.3
5 to 10 714 10.9
10 to 15 485 7.4
15 to 20 332 5.1
20 to 30 463 7.0
30 to 40 352 5.4
40 to 50 255 3.9
50 to 100 794 12.1
100 to 200 574 8.7
Over 200 283 4.2
Totals 6,570 100.2

Mr. McFall

To ask the Secretary of State for Defence what is the maximum radiation dose, rounded to the nearest milliSievert, received by any refit worker in one year during the last three decades; and if he will make a statement.

Mr. Neubert

[holding answer 4 April 1990]: Rounded to the nearest milliSievert, 88 milliSieverts represents the highest recorded annual dose for any worker at the royal dockyards in the past 10 years. Data for earlier years are not readily available and could be provided only at disproportionate cost. The circumstances of this exposure are described in my earlier reply to the hon. Member.

Mr. McFall

To ask the Secretary of State for Defence what is the maximum total radiation dose received by any refit worker over any period, or number of periods, spent as a classified radiation worker; and whether such an individual or individuals are still working as classified radiation workers within nuclear-propelled submarine refit facilities.

Mr. Neubert

[holding answer 4 April 1990]: The maximum total radiation dose recorded for any worker at the royal dockyards registered in the defence radiological protection service's record keeping system is 775.95 milliSieverts. This total dose accrued over the period June 1953 to March 1982. The man is no longer working, having reached retirement age. Data for personnel ceasing radiation work before 1 January 1979 are not readily available and could be provided only at disproportionate cost.

Mr. McFall

To ask the Secretary of State for Defence what is the standard radiation exposure measuring device, issued to and worn by refit personnel during all refit operations; and whether the type of measuring device has changed since the onset of the naval nuclear propulsion programme.

Mr. Neubert

[holding answer 4 April 1990]: The personal radiation dosimeter currently issued to radiation workers monitored for exposure to ionising radiation by the defence radiological protection service, an HSE approved dosimetry service, is the thermoluminescent dosimeter introduced in March 1983. Before this date, and from the onset of the naval nuclear propulsion programme, the photographic film dosimeter was used. Currently, a variety of direct reading dosimeters are used for the monitoring of employees.

Mr. McFall

To ask the Secretary of State for Defence what is the total occupational, whole body equivalent, radiation exposure of all refit workers in the United Kingdom in milliSieverts, for each year since the onset of the naval nuclear propulsion programme; and if he will make a statement.

Mr. Neubert

[holding answer 4 April 1990]: The cumulative radiation doses of all workers in the royal dockyards, for each of the years 1979 to 1989 inclusive, are shown in the table. These figures include the cumulative radiation doses of employees monitored for exposure to ionising radiations by the local issue of direct reading dosimeters within the refit yards. These latter figures have been supplied by, and are included with the permission of, the dockyard contractors, who assumed responsibility for health and safety of persons employed within the nuclear licensed sites at Rosyth and Devonport on 5 April 1987.

Data for earlier years are not readily available and could be provided only at disproportionate cost.

Year Cumulative dose (MilliSieverts)
1989 6,978
1988 5,501
1987 6,837
1986 8,704
1985 11,536
1984 16,680
1983 13,734
1982 11,717
1981 15,276
1980 18,158
1979 17,378

Mr. McFall

To ask the Secretary of State for Defence what limits are adopted for internal organ radiation dose exposure for refit workers.

Mr. Neubert

[holding answer 4 April 1990]: All dose limits adopted by the MOD and its contractors comply with the requirements of the Ionising Radiations Regulations 1985 which are listed at schedule 1 of those regulations.

Mr. McFall

To ask the Secretary of State for Defence what percentage of refit workers are classified as radiation workers; and how these personnel are selected and deemed fit for classification.

Mr. Neubert

[holding answer 4 April 1990]: At present about 25 per cent. of workers at the royal dockyards are designated "classified". The criteria against which these employees are selected and designated as classified persons are specified in regulation 9 of the Ionising Radiations Regulations. Certification that an employee is fit to be designated as a classified person is provided by an appointed doctor, in accordance with the requirement of regulation 9(3)(b) and regulation 16 of IRR85.

Mr. McFall

To ask the Secretary of State for Defence whether his Department maintains an agreement with the United States Department of Defence regarding transfer of information and data about nuclear submarine refit accidents, risk or safety of refit workers.

Mr. Neubert

[holding answer 4 April 1990]: No.

Mr. McFall

To ask the Secretary of State for Defence whether his Department's research into morbidity and mortality among refit workers has considered genetic effects which have passed on to offspring due to exposure of refit workers to radiation in the normal course of their duties.

Mr. Neubert

[holding answer 4 April 1990]: No such research has been undertaken by my Department.

Mr. McFall

To ask the Secretary of State for Defence whether the refit personnel receiving doses in excess of 15 milliSieverts in two or more consecutive years, or three or more separate annual doses, were thereafter removed from the occupation or positions where they had been or likely would be in future, subject to such doses; and if these personnel were advised of the radiation risk they were undergoing.

Mr. Neubert

[holding answer 4 April 1990]: It is not my Department's policy, nor to my knowledge that of any other United Kingdom employer, to remove persons receiving, as a result of their occupational external exposure to ionising radiation, doses in excess of this level, whether in two or more consecutive years or in three or more separate annual doses. With regard to the hazards associated with working with ionising radiation, all personnel who are occupationally exposed receive such information, instructions and training as are required by regulation 12 of the Ionising Radiations Regulations 1985. My Department ensures that such personnel have access to their individual radiation dose records, and receive

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