IR 05000245/1994003
| ML20059L379 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/24/1994 |
| From: | Jang J, Joustra J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20059L377 | List: |
| References | |
| 50-245-94-03, 50-245-94-3, 50-336-94-03, 50-336-94-3, 50-423-94-03, 50-423-94-3, NUDOCS 9402070002 | |
| Download: ML20059L379 (6) | |
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j U.S. NUCLEAR REGULATORY COMMISSION
REGION I
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Repon Nos.
50-245/94-03: 50-336/94-03: and 50-423/94-03 l
Docket Nos.
50-245: 50-336: and 50-423
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License Nos.
DPR-21: DPR-65: and NPF-49 Licensee:
Northeast Nuclear Energy Company i
P.O. Box 270
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Hanford. Connecticut 06141-0270 i
.i Facility Name:
Millstone Nuclear Generating Station. Units 1. 2. and 3 Inspection At:
Northeast Utilities Service Company. Berlin. Connecticut Inspection Conducted:
January 10-14. 1994
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/- ANYY Inspector:
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n C. Jang, Senior Radiation Spialist Date
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L fluents Radiation Protection Section (ERPS)
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'acilities Radiological Safety and Safeguards Branch (FRS&SB)
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Approved by:
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.b Mw I /ih/9(
l Ju i i A. Joustra, Chief, pS, FRS&SB, Dat6
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i Di'sion of Radiation Safefy and Safeguards
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i Areas Inspected:
Announced safety inspection of the projected dose calculation capability
from radioactive liquid and gaseous ef0uent releases.
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Results:
Within the areas inspected, the licensee implemented an excellent projected i
dose calculation. Excellent knowledge of the Radiation Assessment Branch (RAB) staff in
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this area was notewonhy. No safety concems or violations of NRC requimments were
identified.
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9402070002 94012B>
PDR ADOCK 05000245 G
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DETAILS 1.0 Lndividuals Contacted at Northeast Utilifies Sevice Company (NU)
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- R. Crandall, Supervisor, Radiation Assessment Branch j
- W. Eakin, Senior Engineer
- L. Landry, Scientist
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- R. Schmidt, Manager, Radiation Assessment Branch
- Attended the exit meeting on January 14, 1994.
2.0 Purnose i
The purpose of this inspection was to verify the licensee's capability to calculate i
projected offsite radiation doses from radioactive liquid and airborne (noble gases and j
particulates) effluent releases during normal operation.
J 3.0 Responsibility and Procedures The RAB of NU had the responsibility to perform the final offsite dose calculations
and used them for the radiological semiannual effluent reports. These calculations were performed after releases but not used for controlling effluent releases. The Millstone site had the responsibility to calculate projected offsite doses, using its
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Offsite Dose Calculation Manual (ODCM) methodology, to control actual effluent
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releases. The ODCM contained many conservative parameters in order to ensure that effluent release limits would not be exceeded.
The inspector reviewed the following procedures as part of the inspection of the implementation of the Technical Specification and the ODCM requirements.
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o RAB 4-3, Liquid Dose Calculations-LADTAP II J
o RAB 4-4, Gaseous Dose Calculations-GASPAR o RAB 4-5, Gaseous Dose Calculations-AIREM The inspector noted that the above procedures were detailed and well written to allow performance of all necessary steps. The inspector had no further questions in this j
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area.
4.0 PCDOSE Code The PCDOSE code was developed by Idaho National Engineering Laboratory (EG&G Idaho, Inc.) for the U.S. Nuclear Regulatory Commission. The code was designed to calculate the maximum projected radiation dose to an individual and the average dose i
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i to the population due to radionuclides released in radioactive liquid and airborne i
effluent releases from a nuclear power plant. The code was designed for normal i
operation rather than for emergency situations. The code was developed from the -
methodology found in both NUREG-0133 and Regulatory Guide 1.109 (Revision 1).
The PCDOSE code is to serve as a basis of comparison with similar programs
conducted by individual utilities which operate nuclear power plants.
j 5.0 Verification of the Projected Dose Calculation Program During this inspection, the inspector conducted intercomparisons at the NU Berlin facility. The inspector reviewed the ODCM for site specific parameters. The
inspector noted that the licensee used the LADTAP computer code for radioactive -
j liquid releases and the GASPAR computer code for vent release for noble gases and
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particulates, including iodines and tritium. The AIREM computer code is being used
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by NU for elevated releases (375 foot stack) of noble gases and particulates, as well j
as iodines and tritium. Both LADTAP and GASPAR computer codes were developed
and published by the NRC.
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The AIREM code 'was developed and published by the U.S. Environmental Protection
Agency (EPA) in May 1975 (EPA-520/1-74-004). The inspector did not compare the j
AIREM code against the PCDOSE code due to differences in the computer model.
l However, the licensee studied the adequacy of the AIREM code prior to use in 1976.
The inspector reviewed the study results and the results of the AIREM code which -
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compared favorably with actual measured doses from an ion chamber.
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The GASPAR code uses the semi-infinite cloud model and since the Millstone site
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boundary is only about 800 meters from the 375 foot stack, the GASPAR code would grossly underestimate the maximum individual dose due to a overhead gamma cloud.
l Therefore, the licensee determined that the GASPAR code was not appropriate for the Millstone site. The inspector had no further questions in this area.
The inspector evaluated the licensee's computer code by using site specific parameters i
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and release information. The intercomparison results for the liquid, noble gas, and particulates release pathways are listed in Tables 1,2,3,4,5, and 6.
The results of the radioactive liquid release pathway intercomparisons were excellent, as shown in Table 1. During the previous inspection conducted in June 1990, the inspector noted that the licensee conducted a study for zinc-65 (Zn-65)
bioaccumulation factors for shellfish, fish, and lobster. Zinc-65 was measurable in those sample media due to Unit 1 zinc injection performed in 1987. Based on the study the licensee used site specific dose factors for Zn-65. The inspector stated that
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the RAB and Millstone site staff's efforts to determine dose factors for sample media l
were excellent.
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The results of noble gas release pathway intercomparisons were also excellent, as
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illustrated in Table 2.
The results of particulate release pathway (inhalation pathway) and ground plane
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pathway intercomparisons were also excellent, as shown in Tables 3 and 6,
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The results of cow-milk and leafy vegetation pathways intercomparisons were not as good as the others due to the different computer code and dose factors. The NU Ti results were higher than the PCDOSE results with the exception of bone dose from
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milk pathways, as illustrated in Tables 4 and 5. The GASPAR code was published by the NRC in 1980 (NUREG-0597). The GASPAR code is not as current as the PCDOSE code, which was developed in 1989. The PCDOSE code used more current dose factors as well as more current models.
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The NRC currently does not have specific criteria for comparisons. However, up to about a 50% difference in projected dose values is acceptable as long as the cause of -
difference can be identified.
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Based on the above comparisons, the inspector determined that the licensee conducted an excellent projected dose calculation program at NU. The inspector also noted that
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the responsible individuals had excellent knowledge in this area and the effluent control programs as well.
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5.0 Exit Interview
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The inspector met with the licensee representatives denoted in Section 1 of this
inspection report at the conclusion of the inspection on January 14,1994. The inspector summarized the purpose, scope, and findings of the inspection. The licensee acknowledged the inspection findmgs.
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Table 1. Dose Projection Comparisons (Release Sources Liquid)
Adult Dose (mrem /quaner)
Bone Liver T. Body Kidney Lung Gi-Lli NU 2. 82E-5 3.86E-2 2.53E-5 1.31 E-5 4.36E-5 7.48E-5 NRC 2.76E-5 3.77E-2 2.472-5 1.28E-5 4.26E-5 7.30E-5 Table 2. Noble Gas Dose Projection Comparisons
Beta Air Gnnuna Air Total Skin Total Body (mrad / quarter)
(n. wd/ quarter)
(mrem /quaner)
(mrem / quarter)
NU l.42E-2 6.06E-3 1.02E-2 3.71E-3 NRC 1.42E-2 6.06E-3 1.02E-2 3.71 E-3 l
i Table 3. Dose Projection Comparisons (Release Sources. Paniculates)
Inhalation Pathway. Adult Dose (mrem / quarter)
i Bone Liver T. Body Thyroid Kidney Lung Gi-Lli NU 2.79E-6 4.40E-4 4.37E-4 1.53E-3 4.43E-4 4.35E-4 4.37E-4 NRC 2.79E-6 4.40E-4 4.37E-4 1.53E-3 4.43E-4 4.35E-4 4.37E-4
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Table 4. Dose Projection Comparisons (Release Sources Particulates)
Cow Milk Pathway Adult Dose (mrem / quarter)
Bone Liver T. Body Thyroid Kidney Lung Gi-Lli NU l.46E-4 4.75E-4 3.84E-4 6.89E-2 6.25 E-4 2.65 E-4 3.24E-4 NRC 1.58E-4 3.77E-4 2.78E-4 7.35E-2 5.39E-4 1.50E-4 2.14E-4
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Table 5. Dose Projection Comparisons (Release Sources : Particulates)
Leafy Vegetation Pathway : Adult Dose (mrem /quaner)
Bone Liver T. Body Thyroid Kidney Lung Gi-Lli NU 4.36E-5 8.49E-4 8.21E-4 2.08E-2 8.94E-4 7.86E-4 8.05E-4
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NRC 1.26E-5 6.25E-4 5.47E-4 5.29E-2 7.55E-4 4.44E-4 4.94E-4 Table 6. Dose Projection Comparisons (Release Sources : Particulates)
Ground Plane Pathway Total Skin Total Body (mrem /quaner)
(mrrm/quaner)
NU l.14E-5
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NRC 1.13E-5 1.38E-5 l
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