NESC0992 LADTAP2.

1. NAME OR DESIGNATION OF PROGRAM:  LADTAP2.

3. DESCRIPTION OF PROBLEM OR FUNCTION

LADTAP2 performs environmental  dose analyses for releases of liquid effluents from light-water nuclear power plants into surface waters during routine operation. The analyses estimate radiation doses to individuals, population groups, and biota from ingestion (aquatic foods, water, and terrestrial irrigated foods) and external exposure (shoreline, swimming, and boating) pathways. The calculated doses provide information for National Environmental Policy Act (NEPA) evaluations and for determining compliance with Appendix I of 10 CFR 50 (the "ALARA" philosophy).
The program consists of a hydrologic model chosen to represent mixing in the effluent impoundment system and the receiving surface  waters and the exposure pathway models which estimate exposure of selected groups at various water usage locations in the environment. Two types of population doses are calculated. An ALARA analysis is performed based on exposure of people within 50 miles of the site, and a NEPA analysis is performed based on exposure of the entire U.S. population to effluents from the site. A population-dose analysis prepared in the form of a cost-benefit table presents the total-body and thyroid doses from each radionuclide released and the population doses (total-body and thyroid) per curie of each radionuclide released.

4. METHOD OF SOLUTION

The impoundment system is represented by one of four hydrologic models: direct release to the receiving water, linear flow with no mixing (the plug-flow model), linear flow through the impoundment with partial recirculation through the reactor (the partially mixed model), or complete mixing in the impoundment with partial recirculation through the reactor (the completely mixed model). The last three account for radiological decay during transit through the impoundment system. Optional models are available to estimate dilution in nontidal rivers and near-shore lake environments.
The consequence calculation part of LADTAP2 starts with the water concentration at a specific usage location in the environment. The effluent concentration from the impoundment system is related to the water concentrations at the usage locations by two parameters, a diluation factor and a transit time (for radiological decay in transport through the surface water system). The water concentration at the usage location is applied to specific pathway models to esimate the resulting exposure. The pathways included are: ingestion of aquatic foods, such as fish, invertebrates, and aquatic plants; external exposure to shoreline; external exposure to water through boating or swimming; ingestion of drinking water (freshwater sites only); and ingestion of irrigated terrestrial food crops.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Maxima of -
200 nuclides in the release source term
19 sport fish harvest locations
19 commercial fish harvest locations
19 sport invertebrate harvest locations
19 commercial invertebrate harvest locations
  8 body organs
The radionuclide library contains data for 169 radionuclides.

6. TYPICAL RUNNING TIME

The longest running sample problem required 23 CPU seconds on a DEC VAX11/780 and 15 CPU seconds on a DEC VAX11/785.

Each of the three cases ran at NEA-DB on a VAX 8810 computer in less than 4.5 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM

The usage factors contained in Regulatory Guide 1.109 have been included as standard assumptions, but these may be replaced easily with site-specific data.

8. RELATED AND AUXILIARY PROGRAMS

LADTAP2 is a replacement for the earlier NRC LADTAP, Liquid Annual Doses To All Persons, program. LADTAP was written by U.S. NRC Radiological Assessment Branch staff. GASPAR (NESC 963) and GASPAR2 calculate doses from radionuclide releases to the air.

10. REFERENCES

- Calculation of Annual Doses to Man from Routine Releases of
  Reactor Effluents for the Purpose of Evaluating Compliance with
  10 CFR Part 50, Appendix I, U.S. Nuclear Regulatory Commission
  Regulatory Guide 1.109, Revision 1, October 1977 (contained in
  NUREG/CR-1276).
- Estimating Aquatic Dispersion of Effluents from Accidental and
  Routine Reactor Releases for the Purpose of Implementing Appendix
  I, U.S. Nuclear Regulatory Commission Regulatory Guide 1.113,
  Revision 1, April 1977.
- Estimation Aquatic Dispersion of Effluents from Accidental and
  Routine Reactor Releases for the Purpose of Implementing Appendix
  I,
  U.S. Nuclear Regulatory Commission
  Regulatory Guide 1.113, Revision 1, April 1977.
- J.S. Boegli, R.R. Bellamy, W.L. Britz, R.L. Waterfield:
  Preparation of Radiological Effluent Technical Specifications for
  Nuclear Power Plants,
  NUREG-0133, October 1978.
- G.R. Hoenes, J.K. Soldat:
  Age-Specific Radiation Dose Commitment Factors for a One-Year
  Chronic Intake,
  NUREG-0172, November 1977.

- D.L. Strenge, R.A. Peloquin and G. Whelan :
  LADTAP II - Technical Reference and User Guide
  NUREG/CR-4013 PNL-5270 (April 1986)
- L. Eyberger :
  LADTAP2 Tape Description
  NESC Note 88-10 (November 23, 1987)

11. MACHINE REQUIREMENTS:  184 Kbytes of memory are required for execution.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  VMS 4.5.

VMS VS5.0-1 (VAX 8810).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The companion radionuclide library is equivalenced to FORTRAN logical unit 20. The peak working set size is about 390 and the peak page file size about 554.

15. NAME AND ESTABLISHMENT OF AUTHOR

          D.L. Strenge, R.A. Peloquin, and G. Whelan
          Pacific Northwest Laboratory

File name	File description	Records
NESC0992_03.001	Information file	63
NESC0992_03.002	LADTAP2 FORTRAN-77 source	6834
NESC0992_03.003	Input data of sample case 1	54
NESC0992_03.004	Input data of sample case 2	34
NESC0992_03.005	Input data of sample case 3	22
NESC0992_03.006	Library of radionuclide dose factor	2205
NESC0992_03.007	Output list of sample case 1	1421
NESC0992_03.008	Output list of sample case 2	304
NESC0992_03.009	Output list of sample case 3	1975