ML17262A547
| ML17262A547 | |
| Person / Time | |
|---|---|
| Issue date: | 01/04/1979 |
| From: | Levine S Office of Nuclear Regulatory Research |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RIL-0044 | |
| Download: ML17262A547 (4) | |
Text
1.:
.
- UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 JAN 0 4 1979 MEMORANDUM FOR: Harold R. Denton, Director Office of Nuclear Reactor Regulation 0 FROM: Saul Levine, Director Office of Nuclear Regulatory Research
SUBJECT:
RESEARCH INFORMATION LETTER # 44 RADIATION DOSE TO CONSTRUCTION WORKERS AT OPERATING NUCLEAR POWER PLANT SITES Introduction and Summary This memorandum transmits the results of completed research to evaluate the radiation doses received by construction workers at sites where new facilities are under construction next to operating nuclear power plants.
This work was performed by the Battelle Pacific Northwest Laboratory under the direction of the Environmental Effects Research Branch of RES.
In order to comply with the National Environmental Policy Act of 1969, NRC must assess the environmental impact of the construction and opera-tion of nuclear power plants. Because field surveys showed that ex-posure levels were below the point for which personnel monitoring is required, radiation doses received by most construction workers had not been routinely measured. As a consequence, an adequate environmental impact assessment could not be made for the doses to construction workers.
This study was designed to provide a data base which would allow a*
realistic assessment of the radiological impact on construction workers of proposed multi-unit nuclear power plants and to determine whether increased control of the radiation exposure of these workers is warranted.
Methodology Measurements of personnel exposure of construction workers were conducted at four sites where new facilities were under construction: Site A had an operating boiling wat~r reactor; Site B, an operating pressurized water reactor; Site C, two operating boiling water reactors; and Site D, an operating boiling water reactor and an operating pressurized water reactor.
Several hundred or more construction workers were employed at each site during the period of this study. *
- ---"- ---=-=----------~~=========~~-~--~--~--~---=--=*-~--~*~~----~-----.---~
.* _\
Harold R. Denton
- .. Personnel dosimeters capable of measuring beta, gamma, thennal neutron, and fast neutron radiations were worn by selected groups of workers or were placed on water phantoms at selected locations around the site.
Control dosimeters were kept in a lead container at the site and addi-tional control dosimeters were kept off-site. All thermoluminescent dosimeters were calibrated with sources traceable to the National Bureau of Standards. The dosimeters were exchanged on a two or three-month schedule at each site for a period of at least one yearA Site surveys were performed at all four sites when the operating units were at or near full power. The exposure rate was measured by' a system consisting of a Nal(Tl) scintillator, a stabilized gain amplifier, and a nonlinear charge digitizer that electronically corrects for detector response. *This system was calibrated to read out exposure rate directly.
The photon spectra were determined with a Ge(Li) detector system and a 1024 channel analyzer.
Results The results of each excha_nge at each site are given in the enclosed reportll in terms of dose equivalent rates (mrem/mo) for each worker and worker group.
Environmental measurements at each location for each cycle are tabulat"ed in terms of exposure rate (mR/mo) and are presented graphically for each dosi-meter type. Plots of the gamma spectra are reproduced with the most important peaks characterized.
Correlations between operating plant power levels and dosimeter readings were generally poor, indicat.ing that variations in other radiation sources, such as natural background, radiographic sources and radwaste shipments, had a greater effec*t on the meas.urements *. For most worker groups, such as carpenters, painters, pipefitters, etc., the average dose equivalent rates were much less than 10 mrem/mo* greater than the off-site controls. Safety engineers at Site B received the consistently highest dose equivalent above background, estimated at 180 mrem/yr. No evidence of low-energy photon or
.beta radiation was observed; very low levels of fast neutrons were observed on some exchanges with the highest reading 10 mrem/mo.
Most of the environmental do~imeters located outside the operating units showed exposure levels at or near background levels. The h_ighest readings were found near radwaste facilities and refueling areas at the operating units.
16 At Site. A there was evidence of exposure to high energy photons from N.
l/
- Radiation Doses to Construction Workers at Operating Nuclear Power Plant Sites, NUREG/CR-0426.
Harold R. Denton Future Work All work in this area ttas o.een terminated ..
Conclusions and Reconmendations Although Battelle concludes th.at th.ere appears to be no radiation ex-posure problem for construction workers, such a conclusion should be reviewed by the NRC staff.
The results presented in the enclosed report can be used by your staff in preparing the environmental impact statements for construction of multi-unit power plants. For further information on this study, please contact Dr. Judith D. Foulke (427-4358).
w~
~aul Levine, Director Office of Nuclear Regulatory Research
Enclosure:
- c-**CC>"._-.=*-~*-~~-=:-=:-*=, ;.=.-=_;,~=,=,,=:=_._=,::,:=:'-;<;:--*;*C.-=oc::o:,c=~,~;.:;._,~7.i'=::;::=:.:~.-- - - - - - -- - ---- --~
. -
- ___ _,.___:.~~~.. ~,g:,,.,,;:*~-.. -..:.;,.**,**~':,::;./.Jt~~r.~*;/* '~~- :.:. _____ ~ ** --~~-;: . *~"i.-.~~~-, ..'1..1.l:... **........-...~-~~"-'-~""'-'~i*. c.-.
... v ...: . - . " ' .., ,., "'
-/
\
. - ,:.A Harold R. Denton . ;:' -~:* .
Fut'!re Work All work 1n thf s area has been tenntnated. . *. -*~*
Conclus1ons and Reconmendatfoni "'.'.
- _,. .. .*. -~:;-*.
Although Battelle .concludes that there_, _.JJ>pe*r.s _to be no racitation .M"!,-~,--~L posure problem for.construction ~rkers,-*uc;ta c:oncl111ion-shov1d.be * .:
reviewed by the -NRC staff. *. ,,,,._, :..*};* :..... ,_, ~ :~ s;-'I.:;\. ;,;: ..:.,_,_ --~"'.,,. &\,j_.;;;,..,,.. . ":~, +.:.*:;:-):.*y,..:;
- - ._,. ~* ,
- .~*-.:* ~;-~ ~.;f.'.. *;*c. tf ~.:* .:t_r:. :: } :* . ~ i t :*:,. ;::..:*"; *:.~ i: ~ .: ,,.-.t*c;' *. :_;;* ~r ': .;:* * --~'f,- -~: '1' i'~*f-1 ,,~.- *.f(P,.;* * -~~~1 *'".:f~~t. ;".:~*~:. "i. *,{tt~\ *,~_.,t The results *presented h* the enclosed report can be used &,y your staff in preparing the env1rQnmental 1mpact stateme"ts for cons.tntct,1on of**. q*'~:
multi-unit _power plants. For further 1nfe>l'.'lftat1on _on .tbfs ~tt,~".Pletse __ : ...
~ntact :*Or~>,J,udf~h. ~q,.~foulke (4~7-4358). ,;*'-'ii*~:t*:;:~(* 1 ( .. _. C'. fr-~*".:,*':** *e-~~c .. ,
.\ '..
Enclosure:
NUREG/CR-0426 \* :-
- -:.* ~: 1 t~~-~i in~-: :J"i rt;\:~---:~*-
DISTRIBUTION: ,_
Central File CHRONO CIRC JFoulke .
FSwanberg, Jr.
JDavis
.. R~tf8BaY~~ ' ~ . ~ *.: .*.. :
RBudnitz SLevine
-i I
t . ~~ .
. -*:* ...... *---~ -*
- ***---------* f{:;/J.*--~---*'"*-: - . fr/'l'J
~ine RES ; *. _...
- _; . RES 7 *.
.L--RScroggins -RBudnitz 1'" l 2/'V-/78 *12/1.. ~78 OFFICE . .
- U. * ' GOVKl'INIUUOT PRtNTING Ol'l'IC:EI 197.&-11&9-IH