United States Nuclear Regulatory Commission - Protecting People and the Environment

Offsite Dose Calculation Manual (Generic Letter 79-03)


GL79003 

                              UNITES STATES 
                      NUCLEAR REGULATORY COMMISSION 
                         WASHINGTON, D. C. 20555 

                             January 18, 1979 

ALL POWER REACTOR LICENSEES 

Gentlemen: 

By letter dated November 15, 1978, you were requested to submit Radiological
Effluent Technical Specifications and provide for NRC approval your Offsite 
Dose Calculation Manual (ODCM). During the recent seminars held at the NRC 
Regional Offices, we received numerous requests for additional guidance on 
the content for the ODCMs. The attachment to this letter provides guidance 
on the general contents of the ODCM to aid you in its preparation. 

                                   Sincerely,  


                                   Brian K. Grimes, Assistant Director  
                                        for Engineering and Projects 
                                       Division of Operating Reactors 

Enclosure: 
General Contents of the 
     ODCM
.

                     GENERAL CONTENTS OF THE ODCM* 

Section 1 - Set Points 

Provide the equations and methodology to be used at the station or unit for 
each alarm and trip set point on each effluent release point according to 
the Specifications 3.3.3.8 and 3.3.3.9. Provide the alarm and control 
location, the monitor description, location, power source, scale, range and 
identification number, and the effluent isolation control device, its 
location, power source and identification number. If the set point value is 
variable, provide the equation to be used to predetermine the set point 
value that will assure that the Specification is met at each release point, 
and the value to be used when releases are not in progress. If dilution or 
dispersion is used, describe the on-site equipment and measurement method 
used during release, the site related parameters and the set points used to 
assure that the Specification is met at each release point, including any 
administrative controls applicable at the station or unit. The fixed and 
predetermined set points should consider the radioactive effluent to have a 
radionuclide distribution represented by normal and anticipated operational 
occurrences. Other features, such as surveillance requirements and the 
calibration method, should be addressed. 

Section 2 - Liquid Effluent Concentration 

Provide the equations and methodology to be used at the station or unit for 
each liquid release point according to the Specification 3.11.1.1. For 
continuous and/or batch releases, the assumptions used for manual and 
automatic termination of releases should be provided. For batch releases, 
the calculational methods, equations and assumptions used, together with the
pre-release and post-release analyses should be provided. Other features, 
such as surveillance requirements, sampling and analysis program, detection 
limitations and representative sampling should be addressed. 

Section 3 - Gaseous Effluent Dose Rate 

Provide the equations and methodology to be used at the station or unit for 
each gaseous release point according to Specification 3.11.2.1. Consider the
various pathways, release point elevations, site related parameters and 
radionuclide contribution to the dose impact limitation. Provide the 
equations and assumptions used, stipulating the pathway, receptor location 
and receptor age. Provide the dose factors to be used for the identified 
radionuclides released. Provide the annual average dispersion values (X/Q 
and D/Q), the site specific parameters and release point elevations. Other 
features, such as surveillance requirements, sampling and analysis program, 
detection limitations and representative sampling should be addressed. 

*The format for the ODCM is left up to the licensee and may be simplified by
tables and grid printout. Each page should be numbered and indicate the 
facility approval and effective date. 
.

                                  - 2 - 

Section 4 - Liquid Effluent Dose 

Provide the equations and methodology to be used at the station or unit for 
each liquid release point according to the dose objectives given in 
Specifications 3.11.1.2. The section should describe how the dose 
contributions are to be calculated for the various pathways and release 
points, the equations and assumptions to be used, the site specific 
parameters to be measured and used, the receptor location by direction and 
distance, and the method of estimating and updating cumulative doses due to 
liquid releases. The dose factors, pathway transfer factors, pathway usage 
factors, and dilution factors for the points of pathway origin, etc., should
be given, as well as receptor age group, water and food consumption rate and
other factors assumed or measured. Provide the method of determining the 
dilution factor at the discharge during any liquid effluent release and any 
site specific parameters used in these determinations. Other features such 
as surveillance requirements, sampling and analysis program, detection 
limitations and representative sampling should be addressed. 

Section 5 - Gaseous Effluent Dose 

Provide the equations and methodology to be used at the station or unit for 
each gaseous release point according to the dose objectives given in 
Specifications 3.11.2.2 and 3.11.2.3. The section should describe how the 
dose contributions are to be calculated for the various pathways and release
points, the equations and assumptions to be used, the site specific 
parameters to be measured and used, the receptor location by direction and 
distance, and the method estimating and updating cumulative doses due to 
gaseous releases, the location direction and distance to the nearest 
residence, cow, goat, meat animal, garden, etc., should be given, as well as
receptor age group, crop yield, grazing time and other factors assumed or 
measured. Provide the method of determining dispersion values (X/Q and D/Q) 
for short-term and long-tem releases and any site specific parameters and 
release point elevations used in these determinations. Also, provide the 
criteria for determining short and long term releases. Other features such 
as surveillance requirements, sampling and analysis program, detection 
limitations and representative sampling should be addressed. 

Section 6 - Projected Doses 

For liquid and gaseous radwaste treatment systems, provide the method of 
projecting doses due to effluent releases for the normal and alternate 
pathways of treatment according to the specifications, describing the 
components and subsystems to be used. 

Section 7 - Operability of Equipment 

Provide a flow diagram(s) defining the treatment paths and the components of
the radioactive liquid, gaseous and solid waste management systems that are 
to be maintained and used, pursuant to 10 CFR 50.36a, to meet Technical 
.

                                  - 3 - 

Specifications 3.11.1.3, 3.11.2.4 and 3.11.3.1. Subcomponents of packaged 
equipment can be identified by a list. For operating reactors whose con-
struction permit applications were filed prior to January 2, 1971, the flow 
diagram(s) shall be consistent with the information provided in conformance 
with Section V.B.1 of Appendix I to 10 CFR Part 50. For OL applications 
whose construction permits were filed after January 2, 1971, the flow 
diagram(s) shall be consistent with the information provided in Chapter 11 
of the Final Safety Analysis Report (FSAR) or amendments thereto. 

Section 8 - Sample Locations 

Provide a map of the Radiological Environmental Monitoring Sample Locations 
indicating the numbered sampling locations given in Table 3.12-1. Further 
clarification on these numbered sampling locations can be provided by a 
list, indicating the direction and distance fran the center of the building 
complex of the unit or station, and may include a descriptive name for 
identification purposes. 
Page Last Reviewed/Updated Monday, May 13, 2013