ML20086J562

Forwards Comments on Licensee Summary of Decommissioning Process of Univ of UT AGN-201 Reactor 107,Final Rept,Rev 1

ML20086J562
Person / Time
Site:	05000072
Issue date:	07/13/1995
From:	Adams W OAK RIDGE ASSOCIATED UNIVERSITIES
To:	Murray B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20086J534	List: ML20086J562
References
NUDOCS 9507190111
Download: ML20086J562 (14)

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July 13,1995 i Mr. Blaine Murray i U. S. Nuclear Regulatory Commission l Region IV  ;

611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 f

SUBJECT:

DOCUMENT REVIEW "A

SUMMARY

OF THE DECOMMISSIONING l PROCESS OF THE UNIVERSITY OF UTAH AGN-201M REACTOR NO.  ;

107, FINAL REPORT, REV.1", UNIVERSITY OF UTAH (DOCKET NO.

050-072)

Dear Mr. Murray:

j The Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute l for Science and Education (ORISE) has reviewed the subject document and the licensee's  !

responses to a previous ESSAP document review letter dated on July 26,1994. In general, it is the opinion of ESSAP that the document still lacks certain information/ data which would {

cnable the reader to determine the tme and complete radiological status of the site. The data l presentation is inadequate and inconsistent and difficult for the reviewer to follow. It was the  !

intent of the original document review letter to provide guidance to help the licensee understand j l

what items should be included within the report and which items needed to be clarified for better understanding. Although each comment was addressed by the licensee, ESSAP does not feel  :

that the licensee completely understood the intent of the comments. The inclusion of additional information, as described in the attached comments, many which are repetitive of the July 26, i 1994 comment letter, would substantially improve the thoroughness and technical quality of the  ;

i document. Further direction from the NRC, in terms of survey scope, is requested by ESSAP to enable preparation of a proposed survey plan. .

The attached comments are offered for your consideration. If you have any questions or  ;

I comments please contact me at (615) 576-0065 or William L. (Jack) Beck at (615) 576-5031.

i Sincerelv, )

\ Y Wade C. Adams i Health Physicist / Project 12ader l Environmental Survey and n Site Assessment Program om ts o c3 g8E WCA:tsf oo 00 Do Attachment

.a 2 cc: R. Uleck, NRC/NMSS/TWFN/7F27 E. Abelquist, ORISE/ESSAP

@@ D. Tiktinsky, NRC/NMSS/TWFN/8A23 W. Beck, ORISE/ESSAP p PMDA, NRC/NMSS/TWEN/SA33 File /263 ox l

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DOCU3fENT REVIEW  !

A SUM 31ARY OF TIIE DECO 31311SSIONING PROCESS  !

OF TIIE UNIVERSITY OF UTAll AGN-20lM REACTOR NO.107 FINAL REPORT, REV.1 (DOCKET NO. 050-072)  !

GENERAL CONINfENTS l

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1. The primary contaminants at this site and the applicable exposure rate and surface contamination guidelines are not clearly specified. Survey results should be reported in f;

the same units as the guidelines (dpm/100 cm2 ) to permit guideline comparison and  !

determination of compliance. The data provided in this report are not sufficient to l

, demonstrate compliance with the NRC surface contamination guidelines. For example:  ;

The licensee's response was to add Appendix I. ESSAP expected the licensee to list l the individual radionuclidest instead the licensee listed the " expected contaminants"  !

as "No contaminants are expected....." The expected or previously determined radionuclides of concern would help in the determination of which guidelines to use.

The licensee listed " exposure rates" as "only background levels were detected" and  ;

" contamination guidelines" as "any counts exceeding background required l remediation." Therefore, the licensee again did not identify the radionuclides of l concerns or the NRC guidelines used for comparison with their data. Also, the l 2

licensee listed a wipe release limit as "2000 dpm/100 cm 2

" for a 300 cm area. It i is also stated in their response that " Appendix II and I hase been updated to express  !

contamination limits in epm for all wipes, and exposure rates for the final direct  ;

surveys." Contamination limits should be expressed in the same units as the NRC guidelines and typically, direct (fixed) measurements are expressed in units of dpm/100 cm2 and not in terms of exposure rates (mR/hr).  !

l The licensee states on page 13 that "a GM contamination meter was used for direct {

metering," however, the licensee stated that the GM meter was held one inch from '

the surveyed surfaces; typically, the detector is held approximately one centimeter from the surface. Was the calibration of the meter performed at one inch from the calibration source?

(a) In many cases the report states that the measurement was collected over the entire i surface of an item. The NRC guidelines state that surface contamination should I not be averaged over more than 1 square meter. For objects of less surface area, l the average should be derived for each object. Was the entire surface area of the item less than I square meter? l The licensee states that " parts smaller than I square meter will be averaged and updated in this manner." Where was this performed?

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(b) flackground data should be provided. Different surfaces have different i backgrounds, such as metal and concrete. Were these types of background differences accounted for during the final survey data calculations? It was not clear how surface activities were calculated from individual measurements.

Please explain the background fluctuations (See Specific Comment #14).

2. In general, it is the opinion of ESSAP that the documentation lacks certam information/ data that are consistent with that provided from facilities in which similar types of work have been performed. A final status report should provide all the necessary  !

information to allow the reader to evaluate the final radiological status of the items / facility in question. Further detail should be provided for the technical reviewer to evaluate the adequacy of the final status report. This information should include:

(a) General infonnation such as a site history and description and the objectives of the survey activities.

Typically, site histories and descriptions are located at the beginning of reports and not in an Appendix. Perhaps it would have been more i appropriate to reorganize the entire report and follow the recommendations within Draft NUREG/CR-5849 in preparing the report.

(b) Methodologies for:

(1) surface scans The licensee did not describe the surface scan methodologies. Perhaps the description of surface scans could read as follows: Typically, surface scans ,

are performed by passing the probe (detector) slowly over the surface with the distance between the probe and the surface at approximately I cm.

Identification of elevated levels are based on increases in the audible signal or the deflection of the ratemeter needle.

(2) direct measurements The licensee did not describe the direct measurement methodologies. Perhaps the description of direct measurements could read as follows: Typically, direct measurements are performed on surfaces to determine direct radiation levels. Count rates are usually integrated over 1 minute in a static position, and the activity levels converted to dpm/100 cm2 by dividing the net rate by the 4r efficiency and correcting for the active area of the detector.

(3) grid block averaging There was no indication in the report if grid block averaging was performed on building surfaces.

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(4) miscellaneous sample collection if applicable (drain, vents, residues)

Except for the collection of a water sample, there was no indication in Appendix I as indicated by the response, if miscellaneous (concrete bloch, brick, residue, etc.) samples were collected.

(5) calculations of surface activity measurements and MDA determinations Please provide example calculations with formulas used to determine surface activity levels, removable activity levels, and MDAs. On page 14, a release limit of 250 cpm was instituted as an administrative control. This limit was established by doubling the expected average background count (125 cpm),

thus a release limit of 250 cpm gross was established. ESSAP requests that the calculations used to determine the "2000 dpm/100 cm2 .' limit he j provided. If the average background is 125 cpm, then the release limit of l 250 cpm would lead to a net count of 125 cpm; which in ESSAPs calculation, assuming the efficiency is 20% and the area of the GM detector is 20 cm 2, then the result would be 3,125 dpm/100 cm2 . Using the example provided on page I4 for the survey on March 25,1988 when the background was 50 cpm.

if the release limit was 250 cpm, then the net count would have been 200 cpm and the result would have been 5,000 dpm/100 cm2 . This is at the average guideline level for uranium contamination. ESSAP contends that the licensee has not demonstrated compliance with guidelines.

(c) Instrument calibration and QC procedures (i.e. routine operational checks)/ operating parameters (including efficiencies, backgrounds, and detection capabilities)

Were the instrument calibrations dettrmined with 2r or 4x configurations?

What are the respective MDAs for the instrumentation?

(d) Procedures for evaluating results, relative to guidelines and conditions.

I Results were not compared to NRC guidelines; the NRC guidelines are not provided in the report.

3. Uranium is mentioned as a possible contaminant, and in some cases, only alpha measurements were performed. Measurements of beta activity levels, rather than alpha activity levels, provide a more accurate representation of uranium surface activity, due to conditions of building surfaces, (e.g., dusty, porous, or rough), which may selectively attenuate the alpha activity. Therefore, due to site conditions, it may be more appropriate to use beta activity levels for comparison with the guideline values.

Throughout Appendix I, it is mentioned that direct measurements were performed at 1 inch from the surface; is this appropriate for alpha measurements due to attenuation of the alpha particles by surface conditions and the distance the alpha particle would have to travel in air? The licensee did not address this concern.

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4. The quality of data presentation and report preparation is insufficient. Although data are provided, it is not clear as to how the data was compared to the NRC sur!xe contamination guidelines.

The methods of data presentation and report preparation are still insufficient.

Although the raw data (e.g., for removable surface contamination and fixed contamination) are provided, the results are not tabulated and presented in terms of the units for direct comparison to the NRC surface contamination guidelines.

5. The report presents the results, but does not provide a discussion and/or assessment of the data. ESSAP recommends that information be included that discusses the final status of the decommissioned areas.

As in comment 4 above, the licensee has not demonstrated compliance with NRC guidelines. In essence, the guidelines have never been established by the licensee:

instead, the licensee refers to guidelines as "any exposure rate above background  ;

requires remediation," "any counts exceeding 250 cpm gross required remediation."

or "any counts exceeding background required remediation." These are not guidelines: they are administrative controls used by the licensee; however, the licensee should demonstrate that their controls met the NRC criteria (and should list the criteria).

It is also mentioned several times within the report that there were areas where the instrmnentation was to large to fit. The NRC guidelines state that " Surfaces ...

which are likely to be contaminated hut ... (are in a) ... location as to make the surfac- inaccessible for purposes of measurement shall be presumed to he contaminated in excess of the limits." What is the radiological status of parts from the Core Fuel Component surveys?

6. Figures, when provided, are not drawn to scale or labeled clearly. Figures should also be labeled with the direction and should have a figure title and a legend. l i

There are some figures which still do not have a scale or a figure title (page G67).

7. It is not clear from the report.which items or rooms / areas are to be released for unrestricted use. Will the AGN Reactor Room (Room 1205-E) be released? If so, were there other surveys performed on floors, walls, ceilings, and penetrations into this area!

Since the licensee indicates in their response that no rooms are to be released to l unrestricted use, will the NRC need ESSAP to perform survey activities within room 1205-E? It is ESSAPs understanding from the review of this report that ESSAP would be performing confirmatory surveys on non-contaminated parts / equipment which are designated as " unrestricted waste" to be released to a landfill or scrap metal facility (page 12). Is this the NRCs understanding as well?

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8. The last page provided in the report had a page number of xxv. Was this page intended to be in this report, and, if so, are there other pages that are missing?

ESSAP concurs with the licensee's response.

SPEciric Com1ENTS Text

1. Page 1: The first paragraph states that the report is a brief summary of the decommissioning activities that complied with the NRC approved decommissioning plan.

ESSAP would like to review this plan since on Page 3, the licensee states that the plan "contains in detail the steps and procedures that were used to decommission the AGN-20lM reactor." This information would be helpful in reviewing the documentation and in preparing a confirmatory / radiological survey plan.

The licensee stated that "a copy of the plan will be attached to the amended final decommissioning report." ESSAP did not see a decommissioning plan in the report; perhaps the licensee is referring to Appendix B which contains the "Completetl Disassembly Procedures" which is a detailed checklist of procedures that were performed but is not a plan in itself.

Appendix A: Parts list and location

2. Page A3: The figure is blurry and difficult to read.

Revision made.

Annendix B: Disassembly procedures

3. Pages B2-B5: Provide an explanation as to why some of the procedure steps were not performed (marked NA).

The licensee states that the " AGN reactor was already partially disassembled by the previous administration's decommissioning activities." Does the licensee have the original data from the previous administration's activities? If so, this data should also be provided with the final report. This final report should include any surve.t plans and results of previous survey activities.

4. Page B6: This page is missing.

The revision was made.

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5. Page B7: Provide an explanation as to why Form NEL-104 is incomplete; this form is the check-off list for the defueling procedure.

The licensee's response was that "defueling was conducted by the previous administration.....Afler conversation with personnel from this administration it was determined that the form NEL-104 was followed in detail during the defuelhig.

l Unfortunately the completed version of this form can not be found."

l Defueling of the reactor was an important step in the decommissioning process. A copy of the defueling decommissioning survey plan should be added to the final report since form NEL-104 is only a checklist of defueling procedures. Perhaps the form can be completed and signed by Mr. Bennion as having been completed and text be added that addresses the loss of the original form. Would this be sufficient for the final report?

6. Page B8: This form should be labeled NEL-106.

This revision was made.

7. Page B12: Is an adequate measurement sensitivity achieved for a smear by gamma spectrometry?

Ilow is the detector calibrated for a smear geometry and can the formulas used for the calculations he provided?

8. Page B13: The handwritten data is difficult to read.

I ESSAP concurs that a cleaner copy has been provided.

1 Aynendix E: Parts to be disposed of as unrestricted waste  !

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9. There were no survey results attached for these parts (in this section) and the copies of the pictures (photographs) were poor. Please describe, in more detail, the survey procedures used for the alpha, beta, and gamma contamination surveys (See General Comment 2).

ESSAP concurs that the survey results are provided in Appendix G; however, there are no sizes or dimensions listed for these parts. Were activity levels determined over the entire surface of the part (Refer to comment 1(a))? Again, direct counting was performed with a TBM-3S detector and the results reported in mR/hr instead of dpm/100 cm2 . The licensee did perform alpha activity direct measurements, but as mentioned in General Comment #3, beta activity measurements would provide a more accurate measurement of residual surface activity. And again, for removable activity, the LSC used had very low efficiencies for H 3 and C". Were alpha activity measurements performed at one inch from the surface (Refer to General Conunent

1. 3). The survey procedures for the surveys of these parts were not provided as requested.

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Appendix G Survev results

10. Pages G3 and G4: It was stated that the exterior of the AGN reactor was surveyed "using both direct metering and swipes and have found no removable contamination

• Was any fixed contamination found? A TBM-3S was used for the surveys for beta contamination, were there any surveys performed for alpha contamination? It a recommended that an explanation be provided for the data.

Was a procedure written for the exterior survey of the AGN reactor? If so, can it he provided or attached to the final report? It is stated in the licensee's respome that "no fixed contamination was found" and that " alpha contamination swipes were not performed during this survey." This information should be provided to "

complete the report and not leave gaps in the data for future questioning by a reviewer.

11. Page G7: The licensee states that the first stage of the survey of the concrete block uscJ for shielding involves scanning the surface (one side) of the concrete block (presumably the side that faced the reactor). If the block was acceptable, it was placed on a pallet with the monitored side face down. The licensee then states that the "second stage of the survey therefore involves passing the frisker over this surface of the block. " It is not clear as to which surface the licensee is referring.

The licensee's response indicated that surveys were performed on layers of blocks and not on individual blocks. It is also stated in the report that if the blocks are below acceptable activity limits the blocks will be released to a "preapproved contractor for final disposition." Should there be a final confirmatory survey for the release of the blocks?

12. Page G8, third paragraph: The licensee states that " blocks exceeding a count rate et 250 cpm on any surface will be rejected as contaminated material." Background count rates ranged form 60 cpm to 150 cpm. Provide additional information for the justiGeation of using 250 cpm as the " criterion for rejection of concrete block as contaminated material. " and explain how this information compares to the release guidelines. Has the possibility of activation of the concrete block and any structural reinforcement bars been considered?

ESSAP is unfamiliar with the Technical Associates TBM-3S GM detector.

According to the example calculation within the licensee's response, the active area of the detector would have to be 100 cm2 ; is this a correct assumption? Also in the response, the licensee states that "the 2000 dpm/100 cm 2 limit is set to be conservative by a factor of two." ESSAP believes that to be conservative by a factor of two, the limit should have been 500 dpm/100 cm 2(See response page G4 and the attached specifications for the TBM-3S GM detector).

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As per the second part of the question, the licensee response was "at the power levels produced by the AGN-201.T! reactor (5 Watts,286.55 Watt-hours) activation of any part of the reactor is negligible. 'Ihis is true even of parts located inside the reactor." ESSAP contends that activation is possible and perhaps should be worded as follows: "the activation products produced during the operation of the reactor were short-lived radionuclides that would have decayed by the time of the surven or by the finalizing of the report." And on page DS (and others), the licensee states that "due to the absorbing nature of the wood the parts must be considered contaminated by activation products at 10 mci."

13. Page G13: Explain the meaning of a " cave" background.

The licensee states that "a concrete block cave existed in the lab for temporar,$

storage of activated items from the TRIGA Reactor." Background measurements for the TIBI-3S detectors were performed in this cave to determine if the case background would interfere with the concrete block surveys. How close were the concrete block surveys in relation to the cave? The configuration of the cave itself i would lend to higher then normal backgrounds due to the geometry of the cave and the natural occurring radioactivity with the concrete blocks of the cave itself.

14. Page G21: It is not clear as to why maximum readings are less than the background ,

reading in some cases. It is also unclear as to why a background reading (with the same

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instrument on the same day) can vary by a factor of almost two (80 cpm to 150 cpmL The licensee states that "in the case of these surveys, the normal fluctuation of i 40 cpm is not included in the report. Therefore, the background should have read 120 40 cpm and hence a needle swing from 80 cpm to 160 cpm on the detection device while counting concrete blocks is not unreasonable." ESSAP contends that the choice of survey equipment may not be appropriate for the direct measurements that were performed. It is ESSAP's experience that a scaler which keeps a count on the number of disintegrations over a specified time frame would be a more appropriate choice for direct measurements. It appears that the blocks were simply scanned and no direct measurements were performed. Please provide more information on how backgrounds were determined and how direct measurements were performed (Refer to Comment 2(c)).

15. Page G22: It is unclear as to which background applied to each measurement.

See Specific Comment #14.

16. Pages G25 - G27: There is no data provided for the " Number Set Aside" column.

ESSAP concurs with the response.

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17. Page G26: One of the measurements exceeds twice the background level. On Page G7, the licensee states that the " criterion for the rejection of concrete block as contaminated material is a measurable count rate in excess of twice the average area background count rate on the day of the measurement." It appears that this measurement exceeds the licensee's criteria. Also, is this criterion appropriate (See Specific Comment #12)?

It is understood that the licensee is using 250 cpm as an administrative guideline for determining if concrete blocks are contaminated. ESSAP's concerns about the use of this method is provided in General Comment #5. ESSAP is concerned that the use of an average expected background of 125 cpm when the actual background for that day was 50 cpm may have lead to some grid blocks being released that were above the contamination limits. Also, a reading of 50 cpm is below the normal fluctuation of 40 cpm (80 to 160 cpm) as indicated in the licensee's response to Specific Comment #14. Is it possible that on this day, there was a malfunction with the detector? What was the acceptance criteria for this detector for it's daily operational check?

18. Page G29: It is unclear as to what the data means. Please provide units and more detail on calculations and procedures (See General Comment #2).

Please provide an explanation on how the experimentally determined conversion factor of 533 cpm /nCill was calculated. The activity listed was 0.56 nCi/l (560 pCi/l) for gamma activity. The licensee states on page 15 that "the release criteria for the AGN's shield water followed the guidelines as stated in 10 CFR 20 Subpart K, 20.2003 for Disposal by release into the sanitary sewerage." The licensee should explain how all the conditions were satisfied and provide the data.

19. Page G32: The data should be provided. Were any alpha measurements performed?

This comment concerned the bricks that originated in the AGN Reactor. Please explain the " Process Knowledge" reasoning for not performing alpha contamination surveys in the thermal columns.

20. Page G37: It is unclear how this data can be compared to guidelines.

Were the results from survey data notes rewritten for greater clarity and where?

21. Pages G42 - G44: This data is confusing, i.e. are there 3 individual measurements for removable contamination or is there only one measurement? How were 3 separate measurements (in cpm) convened to one measurement (in dpm)? Explain how this data is compared to guidelines. Exposure rates are typically measured at 1 m above the surface and not at contact, if compared to the 5 plUh above background criterion.  ;

The first two questions were ansucred; the remaining parts were not addressed.

22. Page G45 - G48: The copied data are difficult to read and understand. j 1

Not much better.

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23. ' Page G53: Provide an explanation for the data. There are several data entries that are

<MDA: the MDA should be provided with the data.

The licensee response was that "any count that reads at background or less for gross counts is considered to be below minimum detectable activity (<MDA). It is recommended that the licensee provide the formula for the calculation of the MDA and provide in the report the calculated MDAs for all of the radiation instrumentation. l l

24. Page G55: Provide an explanation as to why beta gamma fixed measurements were not performed (See General Comment #3).

The licensee's response was that for the external surveys, "a TBM-3S detector )

sensitive to B, y was used to determine exposure levels for the defueling personnel  !

in mR/hr units for fixed contamination." Were Core Fuel Component parts to be l surveyed and released; if so, why weren't direct beta-gamma measurements performed (See General Comment #3)? An explanation should be provided for l items in which the removable contamination is listed in dpm/ entire surface. Were these small areas or were the areas greater than 100 cm 2

? Ilow were detector readings in cpm converted to mR/hr?

25. Page G68: All of the net counts for the smears are listed as zero. It appears that an inappropriate background was used in the calculations since it is expected that there  ;

would be a normal distribution above the background, with some positive and some negative values for net counts. Perhaps the background was high and all numbers that were negative were reported as zero.

I ESSAP feels that the licensee's response was inadequate since there should be a l normal distribution with both positive and negative results. Also, if there were no  :

possibilities of activation products, why on page G66 under " Isotopes used" are activation products and tritium listed?

26. Page G70: Provide an explanation for the data presented on this page.

Refer to Specific Comment #25.

27. Pages G72 - G83: There is no consistency in the presentation of the data. For example. l the units for the direct counting column are reported for each part number while the units for the alpha counts and liquid scintillation counts are reported in the column headings.

It is recommended that the table should have a title and that the heading for each column of data should be provided on each page. Provide an explanation for 0/0 in the LSC column.

Again, beta-gamma counts are in units of mR/hr and not in terms of the NRC release guidelines. The table basically remains the same and the presentation of the data is inconsistent (See original comment above).

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28. Page G75: For Part #86 the columns labeled " Alpha" and "LSC" reports for the data "see below." These data were not provided.

ESSAP concurs with the response.

29. Page G79: For Part #58, and for other parts on some of the following pages, provide an explanation for the data in the alpha column which is listed as 1(0). Also, on Page G82, provide an explanation for Part MM in the "LSC" column where the data is presented as 27/0.

The removable activity release criteria in the licensee's response was 200 dpm/100 cm . This would correspond with the average and maximum criteria for fixed 2

contamination being 1000 and 3000 dpm/ID0 cm , respectively. Is this a correct 2

assumption?

Appendix II: Survey instruments and operation data

30. Page Ill: The efficiencies listed for 11-3 (0.03) and C-14 (0.04) seem quite low.

Typically for liquid scintillation counters, these efficiencies are approximately 40% and 80%, respectively. Provide an explanation.

Please provide more information on the efficiencies used for the liquid scintillation counter and how they were experimentally determined. Were the filter papers placed in the vials without a scintillation cocktail? There are several scintillation cocktails on the market that are environmentally safe and biodegradable; would it have been more appropriate, in order to get a higher efficiency, to have used a scintillation cocktail?

31. Page lil: The calibration sources used to calibrate the thin-window GM probes were C-14, P-32, and Cl-36. Were these appropriate choices for the possible contaminants of concern? Ilow were the different efficiencies applied to different areas? Was sampling and analysis performed to provide information on the nature of the contaminants?

The licensee's response indicated that the sources were used for " efficiency checks";

is this another term for calibration source? The licensee also states that "these sources were used in the absence of any information on what possible contaminants might exist. Using low, medium, and high energy betas give a wide spectrum of efficiencies." If the possible contaminants are not known, then how can it be determined if the appropriate efficiencies were used?

32. Page 112: The Micro-R meter, mentioned in the calibration data, is typically calibrated with Cs-137. Due to the energy dependence of this instrument, the response of this instrument to the gamma energies present should be indicated.

It is ESSAPs understanding that the Micro-R meter's response to gamma radiations is energy dependent. Nal detectors have different responses to different energy levels. Calibration of these meters is typically performed at the factory with Cs-137 sources. Therefore, it is recommended that the Micro-R meter be calibrated with a source that has a similar energy spectrum as the contaminants of concern.

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33. Page H2: Provide a copy of the calibration data for the EPA calibrated detectors.

For the exposure rate meters, is it appropriate to list the efficiencies of the detectors as "within 10% on all usable scales?"

ADDITIONAL CO.m1ENTS

1. Page 5: The licensee states that a copy of the document review (by ESSAP) and their responses to the questions posed in the review and the " relevant page numbers where this i final decommissioning report was modified according to the document review." Please l provide the relevant page numbers where the report was modified.

l It is also stated that "A copy of the NRC approved decommissioning plan for the AGN has also been added as an attachment to this report." ESSAP did not get a copy and the attachment is not listed in the Table of Contents.

2. Page D5: On this page and on others it is not clear if the contamination is fixed or removable.

i 3. Page G5: In explaining some calculations, the licensee states that "to simplify calculations and to remain conservative the detector with the lower efficiency was used for all results on that day. Perhaps it should read "that the lowest efficiency for the detectors was used for all results on that day "

4. Page G41 (and others): For the removable co~ amination the three readings are averaged and then the final result is determined. Fo'. 'h fixed alpha contamination there are two readings, but only the first reading is used .:4 %e calculation of the final result. Also.

the fm' al data is reported as dpm and not in terms of an area i.e., dpm/100 cm2.

5. Page G73: Apparently the unrestricted components mentioned in this section are the only pans that the licensee expects the NRC to perform confirmatory surveys on prior to release. Is this the NRC's position also?

6. Appendix 11: What are the counting geometries for the radiation instrumentation?

7. Anpendix I: Please provide example calculations since it is not clear how administrative release limits were determined and how results were calculated. Please provide more detail on instrument procedures.

8. Page 14: The licensee listed a variable count rate for the exposure rate data.

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(arid mFMw). Thin window is recessed and protected by sturdy grill,

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Instrument will see alpha, beta, and gamma radiston. Antisaturation i circuit will not fall below full scale in high fields. Tested to 100 R/hr.

APPUCATION: hs small size, light weight, and large detector area make this a very useful monitor for surveying bench tops er checking  ;

hands, clothes, and fingertips for almost any radcact.ve contaminaten.

S P E ClFIC ATlON S:

)

Meter: TBM-3: 21/4*: TB4 35:ruggedized 21/2*.

Rangea: 3 ranges, linear: 0 500,0 5,000,0-50,000 epm (0 .15,1.5,15 mR/hr).

Switch Positions: Off, Bar- *st. X100, X10, XI.

Audio: TBMi .. illy mounted speaker: TBM.3S: sona'ert with volume control Deteetor: T-1190

• pancake GM tube * ,

l Diameter: 2*; 5 cm 1

Window Diameter: 1 3/4*; 4.5 cm I W;ndow Thickness: 1.5 matm2 Ouench Gas: Halogen for long ide. l

Background:

Typcal 50 cpm. Thin profile et tube (13 mm) gives low background.

Effic;ency: 100% for all betas and alphas that have the energy to ,

penotrate the thin window. Camma sensJtivity nominalis j 3,000 cpm /uR/hr. (based on Cs137).

l Ph)eleal Olmenslons: 3*; 7.6 cm wide x 51/4*; 13.3 cm long x 2-1/4*; 8 cri bigh (excluding meter and l

bandle.

Feet:

Aeplaceable neoprene feet for easy s! ding on bench or desk top without contaminathg bottom face of instrument or detect 0r,

{

Callbratlon: Single master catibtation pot as well as individual cal pots for each range.

Power: 9 volt " transistor battery: Eveready 1222 c.,r equivajent.

Battory Lliei 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> in normaloperation.

Handle: Swivol type. polishod anodizad atuminum Weight: 22 02; C25 gm TA EHNICAL ASSOQAMS 7051 CTON AVENUE

• CANOO A PARK. CA 9t303 e TELEPHONE tit.sas.7 pas e ray asa.aae.n ne

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