ML17244A205

Rept on 781109 Measurement of Nuc Pwr Reactor Environ to Determine Capability of Existing Personnel Dosimetry Sys at Subj Facil.Results Will Be Forwarded to NRC for Study.Util Cooperation Was Exemplary

ML17244A205
Person / Time
Site:	Ginna
Issue date:	11/24/1978
From:	Block S Office of Nuclear Reactor Regulation
To:	Knighton G Office of Nuclear Reactor Regulation
References
NUDOCS 7812010373
Download: ML17244A205 (6)

Text

NOV 8 4 1978 MEMORANDUM FOR:

G. Knighton, Chief, Environmental Evaluation Branch, DOR FROM:

THRU:

SUBJECT:

S. Block, Environmental Evaluation Branch, DOR L. Barrett, Section Leader, Environmental Evaluation

Branch, DOR NEUTRON STREAMING MEASUREMENTS AT GINNA - TRIP REPORT On November 9, 1978, the first measurement of a nuclear power reactor neutron environment under our RES contract "to determine 'the capability of existing personnel neutron dosimetry systems at operating reactors" was made at Ginna (Rochester Gas and Electric) by Bob Ryan of Rensselear Polytechnic Institute.

In parallel with Ryan's studies, a similar one was made by DOE's Environmen-tal Measurements Laboratory scientists Jim McLaughlin and Robert Sanna.

Prior to the actual measurements, preliminary discussions were held with Ed DeMerit (Nealth.Physicist) and staff merrhers Bernie guinn and Rick Watts.

A short orientation was given by guinn on Ginna's radiation safety program which was followed by a multiple choice quiz on what we had learned and what we knew about radiation in general (e.g., what does ALARA mean2).

At this time I handed guinn a question sheet relevant to Ginna's neutron dosimetry program.

The questions and his response are. shown in Attachment 1.

Me then discussed the areas to be monitored.

On the operating level of con-tainment, neutron spectral and dose equivalent measurements were to be made at the entry to containment (i.e., the equipment and personnel hatches) and two measurements near the streaming cavity in a high dose equivalent rate

. area.

In the middle level, a measurement would be made in an area of inter-mediate dose equivalent rate

( 2 to 6 mrem/hr).

Spectra in the basement level of containment would require overnight exposure of the neutron detectors.

Al-though questions relevant to measurements outside the reactor area its'elf were "brought forth by Block, neither group of experimenters was prepared to make such measurements for this run.

He then proceeded to dress-out into our protective clothing and entered the containment (with the reactor at full power) to locate acceptable areas for

-setting up the instruments to be used for the neutron spectral distribution measurements (Bonner Spheres) and various neutron and gamma personnel dosime-ters.

Using a PNR-4 neutron survey meter and gamma ionization chamber, a neu-tron and ganma survey was made in each measurement area.

This was to assure uniform dose equivalent rates (and presumably spectra) over a wide area

(-20 ft ) since Bonner Spheres aust be separated by sufficient distance to VS'801037~

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Nov q~ ~>8 preclude scattering anomolies from adjacent spheres.

After the dosimeters were located, I departed for return to Bethesda since my part of the program was fait accompli.

Ryan, et al, were to work into the night taking their measurements.

fP exposure in containment indicated -20 mr for gamma and nothing discernable for op neutron sel f-reading pocket chamber.

It should be noted that Ginna uses NTA film as their personnel dosimeters although they use the stay time techniques of Regulator/

Guide 8.14 to estimate per-sonnel dose.

They requested my NRC Form 4, which I did not have, and trusted me when I said that I had not received any'xposure during the past quarter.

They asked me to send tqy lifetime exposure so that they would have it on their computer.

I will send it.

Results of the measurements will be sent by Ryan and KcLaughlin for our 'examination.

It should be noted that Rochester Gas and Electric cooperation was exemplary.

Enclosure:

As stated S. Block Environmental Evaluation Branch Division of Operating Reactors cc:

H. Denton E.

Case V. Stello D. Eisenhut B. Grimes T. Murphy W. Kreger OIaE (3)

J.

Foulke R. Foley, ACRS (16)

T. B. Abernathy, O'.IIE NRC PDR Local PDR J.

Shea E.

Adensam Section B/EEB DISTRIBUTION Central Files EEB Reading G. Knighton L. Barrett S. Block ee HI

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ATTACHMENT 1 uestionnaire of Ginna Neutron Dosimetr Program 1)

Frequency of Containment entry at power 2 per month 2)

Number of personnel in entry "team" minimum 2; average 4

3)

Average length of time for entry 30 minutes 4)

Reasons for entry identi fy 1 eaks; post accident filter sample check; snubber inspection; accumulator samples 5)

Hethod of neutron dosimetry NTA film, Landauer Type Y

film for Thermal 6)

Is it same people each time no 7)

Indi vidual neutron dose 8)

Instruments used for neutron surveys 20 mrem PNR-4