ML19256G271
| ML19256G271 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/17/1979 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Winegrad G MARYLAND, STATE OF |
| Shared Package | |
| ML19256G272 | List: |
| References | |
| NUDOCS 7912280634 | |
| Download: ML19256G271 (7) | |
Text
[enalcg' y
o UNITED STATES E y c.t [g NUCLEAR REGULATORY COMMISSION
[
g.pg> y WASHINGTON, D. C. 205ES 8
Y.v M313.NOa
,e Deckets Nos 50-317 IJ 3'!8 k
ULG Ai W3
/
The Honorable Gerald.. Winegrad Maryland House of Delegates Annapolis, Maryland 21401
Dear Mr. Winegrad:
By letter dated Ncvenber 6,1979 to the NRC's Chaiman Joseph M. Hendrie, you cuestioned the effects of radicactive releases from the Calvert Cliffs Nuclear Power Plant units into the waters of the Chesapeake Bay and the atrosphere.
I have been requested to respond to your letter.
As an overall evaluation of the radioactive releases from Calvert Cliffs, comparisons can be made against two reference points.
First, in the Final Environmental Statetent (FES) for Calvert Cliffs, the staff presented estirates of the annual average releases from the plant over the plant lifetite with a resulting dose to an individual from all pathways of less than 5% of actual background. Second, plant Technical Specifications which control the operation of the plant place limits on the release of radioactive effluents from Calvert Cliffs.
As the reference report by the Maryland Power Plant Siting Program (PPSP-CEIR-2) points out in Tables IV-1a and IV-lb, for most categories of releases the Calvert cliffs units releases were within the lifetime annual average releases predicted in the FES.
However, in the category of noble gases, actual releases were about a factor of three higher than the FES estinate.
It is inportant to note that the FES estimate is an anrual average over a 30-40 year plant lifetime.
Therefore, on a year to year basis alar: releases can and are expected to range greatly below and above the averace.
In the case of Calvert Cliffs, most of the noble gases are released during containment purging.
Preoperational predictions of releases due to purging have always been difficult.
Variations in fuel leakage, primry coolant leakage, and reactor downtime can all have large effects on purge releases.
Reports of releases from the Calvert Cliffs units in 1978 and the first half of 1979 show that noble gas releases continue to be three to four times the FES estimate.
Those reports also shoa that the other categories of rel> ases continue to be within or close to t' e FES estirates.
r Release lirits are set by the NRC c ensure that the radiological impact of ;1 ant releases 's within acceptable bourds.
It is important to note that 1650 236 1912280 e
9 Mr. Gerald W. Winegrad Calvert Cliffs has operated and continues to c:erate within the release liraits cf their Technical Specifications. Therefore, we find that releases frorn the Calvert Cliffs units are within acceptable and safe bounds. Specific response to your twelve questions is provided in the enclosure to this letter.
I trust this information will be useful ir. your legislative work.
Si ncerely, r,
Haro'd E. Denton, Director Offi:e of Nuclear Reactor Re;ul ation
Enclosure:
Specific Response to Questions 1650 237
R Encl asure SPECIFIC RESPONSE TO QUESTIONS GERALD W. WINEGRAD MARYLAND HOUSE OF DELEGATES l
Question 1.
In 1976, BG&E predicted amounts of only 19 radioactive elements entering the Bay as liquid effluents.
Through December 1977 at least 48 such elements were identified.
Is this cause for concern?
Response to Question 1 The NRC has no major concern in this " apparent" deviation for numerous reasons.
First, both the NRC and Baltimore Gas and Electric (BG&E or the licensee) expected to identify many low level radionuclides in the reported releases because of the high detectability for the state-of-the art equipment currently used for in-plant isotopic analysis.
The NRC requires each licensee to report 11 identified nuclides in their environ-mental release reports even tMugh the levels might be orders of magnitude below their maximum permissible concentration (MPC).
Secondly, while the Appendix I submittal for Calvert Cliffs lists only twenty (20) specific nuclides, it also includes an "all others" column which accounts for the other expected low-level radionuclides.
The important matter concerning plant releases is not on numbers of nuclides but the iso-topic quantities which are released.
In our review of Calvert Cliffs we find all liquid releases are both significantly lower than the respective acceptable Technical Specification (TS) requirements and the 'as low as reasonably achievable" (ALARA) design objectives.
Question 2.
Of the 19 predicted liquid radioactive effluents, BG&E's cumulative predictions through December 1977 were frequently underestimated by factors of at least 10 and in the case of Cr-51 the estimates were off by a factor of over 9,000.
Is this cause for concern?
Response to Question 2 The NRC has no major concern on this deviation; however, some connents are relevant.
The underestimation of predicted liquid releases as compared to the actual curies released has been addressed from two considerations:
(1) the environmental impact of the actual releases and (2) the cause for deviations in the predictive methods for the various radionuclides released.
1650 238
/wa n 79 Maw nu-m,m p o l
/
From an environmental consideration, a review of the dose associated with releases indicates substantially lower values than allowed by TS for off-site exposure.
For example, the doses attributed to liquid releases are a factor of E00 better than the design objective for the plant. The exten-sive environmental monitoring data also is supportive of the safe and controlled operation of the Calvert Cliffs units.
In regard to the deviations between projected and actual levels reported, the following items must be considered. The projected release values, as required by the Comission, are developed to identify and evaluate the design effective-ness of the licensee's proposed waste processing system.
The predicted values are based on experimental data input for source tenns and waste processing efficiencies.
Since significant ranges of data exist for these inputs some deviation from these projected values would be expected.
The NRC has on-going reviews which are directed toward improvement of predictive methods.
In the case of Chroniun-51 (a corrosion product),
the deviation is most likely associated with a sensitivity effect from the individual source tenn generation rate, waste processing efficiency and sample analysis detectability.
However, as mentioned previously, the important aspect here is that the licensee's releases and associated doses continue to be well below the established limits for safe operation of the facility.
Question 3.
Has adequate research been done to assess the long tenn impacts of the radiation releases, such as tritium, into the waters of the Chesapeake Bay? What about the cumulative impact on such organisms as oysters and the people who may eat them?
Response to Question 3 Significant amounts of research have been conducted in measuring the effects of low level ionizing radiation to man and monitoring the various environ-mental release pathways in the food chain which ultimately lead to man.
1 Based on this research, acceptable levels of exposure to man (i.e., both internal and external) were defined and these levels were used as a basis in establishing the radiological effluent TS for operating reactors.
Based on the NRC requirements, the annual doses both to the aquatic biota and to humans through the food chain are several orders of magnitude below the dose levels at which radiation effects have been demonstrated.
In addition, confirmatory and supporting research is currently continuing to better define i
the somatic and genetic effects of exposure to low level ionizing radiation.
Some recommended reading as to current Government research and developments include (1) BEIR II Report (EPA 520/4-77-003) and (2) Assessment of Capabilities and Research Needs in the Area of Health Effects of Low Level Ionizing Psadiation (NUREG-0602).
Question 4.
Is the release of liquid radioactive effluents "as low as is reasonably achievable" (ALARA) as required?
Response to Question 4 Based on our review of both the reported radiological dose values (Table IV-8) with supporting data and the NRC guidelines from 10 CFR 50 Appendix I (ALARA),
1650 239
I
. we find the actual dose contributions as corpared to the design objectives for ALARA were more than an order of magni'tude better than required.
It suffices to say that signific ant control has been demonstrated by the BG&E staff to insure that tht. ainimal off-site exposures occur.
Question 5.
Storm water runoff samples at the Calvert Cliffs plant have contained these radioactive isotopes:
Co-60, Co-58, Mn-54, Cx-134, and Cs-137.
Is.this cause for concern?
Response to Question 5 Normally storm water runoff is not contaminated.
However,' under some circumstances runoff can become contaninated.
In 1977, BG&E discovered traces of radioactive cobalt,> manganese, and cesium in sediment at the outfall of the storm water runoff system. This contamination was caused by a leak in an outside tank containing radionuclide liquid.
The leak was repaired and routine sampling of storm water runoff was instituted.
The sampling program now shows no detectable radioactivity in storm water runoff. The sediment in the discharge canal was already contaminated by nomal plant releases, so the storm water runoff added insignificantly to overall contamination of the discharge canal sediment.
Therefore, this is no cause for concern.
Question 6.
Ag-110m has been found in oysters six miles fro
- the plant.
This isotope was not one of the predicted liquid effluentso Is this concentration of Ag-110m in sediments and oysters near and as far as six miles froa the plant cause for concern?
Response to Question 6 As the reference report states, radioactive isotopes of silver (Ag-110n) was not predicted.
However, current NRC models do predict the release of Ag-110m in the liquid effluents of nuclear power plants.
These models also predict the uptake of Ag-110m by aquatic aninals such as oysters'. The effluent monitoring system at Calvert Cliffs does measure the release of Ag-110m and the environmental monitoring progran does measure the con-centration of Ag-110m in aquatic animals such as oyster.
PPSP-CEIR-2 states that the maximum concentration of Ag-110m in oysters found in the environs of Calvert Cliffs to date is 620 pCi/kg.
The environmental monitoring reports from BG&E for the Calvert Cliffs units for the last few years do not exhibit an upward trend in Ag-110m concentration in oysters.
Using the calculational models of Regulatory Guide 1.109, we estimate that the reported 620 pCi/kg would correspond to a maximum dose of less than 0.2 millirem /yr. to the GI tract of an individual from consumption of oysters.
This dose is very small in comparison with the Appendix I unit dose design objective for liquid effluents of 10 millirem / year.
Also, this dose is less than one percent of the annual average dose to the GI tract of 80 millirem due to natural background.
Therefore, we conclude that this concentration of Ag-110m in oysters in the environs of Calvert Cliffs is not cause for concern.
1650 240 Question 7.
Can you comment on the analysis on page IV-19 and the chart at Page IV-21 that Aa-110m, Co-58 and Co-60 doses found in oysters near the -lant produce risk levels vihen eaten by humans that "are ::inuscule compared to the nomal risk levels...of the U. S. population today"?
Response to Question 7 The health effects estinates presented in Table IV-6 of the reference report are reasonable estimates. They are based on references such as the BEIR Report which are the bases of our position on health effects. While the estimates are not the exact values used by the NRC, they are reasonably close. We also agree that health risks of eating oysters (as discussed in Question 6) are minuscule.
Question 8.
BG&C predicted 18 radioactive isotopes in varying amounts would be released to the atorosphere.
However, 45 such iso-topes, some at much higher rates than predicted, have been released. Are these failures to predict and under-predictions cause for concern?
Response to Question 8 The response given for Question 1 is also applicable to Question 8.
Questior.9.
Generating Unit 2 began connercial operation on April 1,1977 so that the cumulative impact measured in the enclosed report only includes Unit 2's impact for nine months.
Are you satisfied that the accuracy of predictions and impacts of cumulative discharges are and will be within safe limits?
7esponse to Question 9 The operation of Calvert Cliffs Units Nos.1 and 2 is governed by TS approved and issued by the NRC.
These TS include limits on releases of radioactive effl uents. These limits are set at values which ensure that the accumulated impact offsite stays within acceptable bounds.
Also, EPA's 40 CFR Part 190 is now in effect and further limits the inpact of effluent releases.
Calvert Cliffs Units Nos.1 and 2 are operating within these limits and thus we conclude that the impacts of release from both units will continue to be within safe limits.
Question 10.
BG&E has recently applied for authorization to nearly double its storage of spent fuel reds.
Is this long tem stcrage, perhaps into the 1990's, cause for conce-n?
Response to Question 10 The Comission issued, on January 4,1978, Amendnents Nos. 27 and 12 author-izing an increase in the nunter of storage positions in the Calvert Cliffs spent fuel pool from 410 to 1,056 fuel asser.blies.
Shortly after this approval, 1650 24I BG&E modified one side of the spent fuel pool with the new high density racks.
This increased the total storage capacity to 728 fuel assemblies.
The recent application you referenced was submitted on July 3,1979.
This application was to modify the other side of the spent fuel pool with fuel racks containing neutron poison material, If arthorized, the fuel assembly storage capacity would be increased t) 1 '48 fuel assemblies.
This change would accomodate operation of both un't', through most of 1987.
Our review of this request will probably not be complete for several months. When it is complete, you will be sent a copy of the safety evaluation.
We will, of course, not approve this proposal unless our concerns are satisfied.
I Question 11.
Are you convinced that the airborne and liquid effluent I
discharges from the Calvert Cliffs plant present no threat to human health or safety?
Response to Question 11 Our response to Question 9 is also applicable to this question.
Based on our review of effluent releases and environmental monitoring analyses, we conclude that the airborne and liquid effluent discharges from the Calvert Cliffs plant present no threat to huran health or safety. As long as Calvert Cliffs operates within the conditions of their TS and 40 CFR 190 this conclusion stands.
Question 12.
Can you corment on the potential for serious calamity given
'the nearness to Calvert Cliffs of the Cove Point Liquid Natural Gas (LNG) facility?
Response to Question 12 The staff has reviewed the effects of a Liquified Natural Gas Accident on the facility of Calvert Cliffs as documented in our a:tached Safety Evaluation dated June 13, 1978. We found that the probability of an accident of significant risk to the Calvert Cliffs facility was acceptably low. The results of our evaluations indicate that the largest contribution to the overall risk arising from the proximity of the Cove Point teminal is from the LNG tanker traffic associated with the teminal. As a result of discussions with the Coast Guard, LNG tanker routes will be controlled by the Coast Guard to assure that safe distances from the plant will be maintained.
Notwithstanding these restrictions designed to prevent large LNG spills impacting the facility, NRC has required BG&E to submit a contingency plan which addresses precautionary action to be taken at Calvert Cliffs if an LNG spill were to occur.
We are presently reviewing this contingency plan.
The low probability of large LNG spills from the LNG storage facility, the control of tanker routes and traffic, and appropriate contingency planning at the Calvert Cliffs plant contine to minimize the risk to the public from the proximity of these facilities.
1650 242