ML20148L904

Forwards Results of Measurements of Radioactive Matl in NRC Phantom on Whole Body Counter.Encl 1 Contains Actual Amount of Each Radionuclide Present,Encl 2 Gives Ratio of Measurements to DOE Values & Encl 3 Gives Recommendations

ML20148L904
Person / Time
Site:	Browns Ferry
Issue date:	11/09/1978
From:	Sutherland J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Niav Hughes TENNESSEE VALLEY AUTHORITY
References
NUDOCS 7811200406
Download: ML20148L904 (5)

Text

o UNITED STATES j i [peMo uf o NUCLEAR REGULATORY COMMISSION kb O 'b*g>

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[ es REGloN 11 C

{c g 101 MARIETTA STRE ET, N.W.

ATL ANTA, GEORGI A 30303 gh o ,[

• y NOV 0 91978 s% . . ..

.s In Reply Refer To:

RII:WJM 50-259/78-15 50-260/78-16 50-296/78-14 Tennessee Valley Authority Attn: Mr. N. B. Hughes Manager of Power 830 Power Building Chattanooga, Tennessee 37401 Gentlemen:

This refers to the inspection conducted by Mr. W. J. Millsap of this office on June 26, 1978, of activities authorized by NRC Operating License Nos.

DPR-33, DPR-52 and DPR-68 for the Browns Ferry 1, 2 and 3 facilities. The results of this inspection are discussed in our Inspection Report Nos.

i 50-259/78-15, 50-260/78-16 and 50-296/78-14 which was enclosed with our I letter to you dated August 31, 1978.

During the inspection, members of your staff measured the amount of radioactive material in an NRC phantom on the mobile whole body counter.

This measuremer.: was also made by other NRC licensees and three Departme: t of Energy laboratories. The results of these measurements are given in te enclosures to this letter.

Enclosure 1 gives the results of the measurements made by your staff, the actual amount of each radionuclide present in the phantom at the time of this measurement, and the ratio of measured to actual amounts. Enclosure 2 gives the ratio of each measurement result to the amount actually present in the phantom at the time of the measure-ment for all measurements made by DOE labotatories and NRC licensees.

Power reactor facility values are denoted by single letters; Department of Energy laboratory values are denoted by double letters. Enclosure 3 discusses general recommendations based on the inspector's observations of these measuremento.

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t Tennessee Valley Authority Should you have any questions concerning this letter, we will be glad to discuss them with you. No reply to this letter is required.

Sincerely,

{

4 / Y/[edu/

. T. Sutherland, Chief Fuel Facility and Materials Safety Branch

Enclosures:

As stated cc w/ encl:

Mr. J. G. Dewcase Plant Superintendent Box 2000 Decatur, Alabama 35602 l

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Enclosure 1 l

Facility: Browns Ferry Facility Designation: A Date of Measurement: June 26, 1978 Measurement Ratio Result Actual (Measured / Actual)

1. Co-60 0.31 pCi 0.24 pC1 1.29

2. Cs-137 0.21 pCi 0.13 pCi 1.62

3. Co-57 0.04 pCi 0.54 pCi 0.07 l 4. Cs-134 Not Reported 0.58 nCi

5. Cr-51 0.10 pCi Not Present

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Enclosure 2 Ratios (Measured / Actual)

Facility Co-60 Cs-137 Co-57 Cs-134

1. A* 1,29 1.62 0.07 NR

2. B 1.08 1.92 1.22 h3

3. C 1.42 1.31 0.66 NR

4. D 1.46 0.85 NR** NR

5. E 2.04 2.77 NR NR

6. F 1.25 0.85 1.22 h3

7. G 1.42 1.62 1.33 h3

8. H 0.88 1.62 0.63 43

9. I 1.63 2.38 0.23 NR

10. J 2.42 2.62 NR NR

11. AA 1.36 1.38 2.97 NR

12. BB 0.78 0.92 0.67 NR

13. CC 1.13 1.38 1.00 NR

• Facility A reported Cr-51 present in the amount of 0.10 uCi.

This was not present in the phantom.

• • NR - Not Reported I

1. • s.

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Enclosure 3

.0bservations by the inspector during the cource of all phantom measurements suggest three general recommendations for the 0mprovement of the whole body counting programs.

1. The spectrum resulting from each whole body count should be observed in its entirety in order that the presence of unexpected radionuclides will be recognized. Several licensees failed to recogrize the presence of the Co-57 apparently because its gamma ent rgy f alls outside a predetermined region of interest.

2. Each licensee should determine the energy response (energ"/ channel) of his detector over the full range of the spectrum. S ev eral licensees had difficulty identifying the Co-57 once the presence of a low energy emitter was recognized because of the unexpected response of the detectors at low energies.

s. Each licensee should consider some sort of intercomparison or independent standard test of his whole body counter (s). A test of this natu- 3 5t reveal problems not immediately apparent to an individual grc':p working independently of all others.

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