ML20245H232
| ML20245H232 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 06/21/1989 |
| From: | Tourigny E Office of Nuclear Reactor Regulation |
| To: | Eury L CAROLINA POWER & LIGHT CO. |
| References | |
| NUDOCS 8906290431 | |
| Download: ML20245H232 (4) | |
Text
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June 21, 1989 Docket Nos.
50-325 50-324 Mr. ' Lynn W. Eury Exeuctive Vice President
' Power Supply Carolina Power & Light Company Post Office Box 1551 Raleigh, North Carolina 27602
Dear Mr. Eury:
SUBJECT:
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION - REACTOR CAVITY NEUTRON DOSIMETRY PROGRAM (TAC N05. 71112 AND 71113)
In conducting our review of your October 26, 1988 and March 30, 1989, submittals relating to the above subject at the Brunswick Steam Electric Plant, we have determined that we will need the additional information identified in the enclosure to continue our review.
In order for us to maintain our review schedule, yr Jr response is reque.sted within.45 days of the date of this letter.
If you cannot provide a full response within the requested time, please provide your full response schedule within 30 days of the date of this letter.
The reporting and/or recordkeeping requirements contained -in this letter affect fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.
Please contact me at (301) 492-1474 if you have any questions concerning this
. letter.
Sincerely, g906290431890621
~"
R ADOCK 0500 4
Original Signed By:
P E. G. Tourigny, Senior Project Manager Project Directorate 11-1 Division of Reactor Projects -1/II.
Office of Nuclear Reactor Regulation
Enclosure:
As stated DISTRIBUTION Docket File NRC PDR BRUNSWICK FILE ONf l
l Local PDR PDII-1 Reading I
1 S. Varga 14-E-4 G. Lainas 14-H-3 E. Adensam 14-B-20 P. Anderson 14-B-20 E. Tourigny 14-B-20 OGC 15-B-18 E. Jordan MNBB-3302 B. Grimes 9-A-2 L. Spessard MNBB-3701 ACRS (10)
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Mr. L. W. Eury Brunswick Steam Electric Plant Carolina Power & Light company Units 1 and 2 cc:
Mr. Russell B. Starkey, Jr.
Mr. H. A. Cole
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Project Manager Special Deputy Attorney General 1
Brunswick Nuclear Project State of North Carolina P. O. Box 10429 P. O. Box 629 Southport, North Carolina 28461 Raleigh, North Carolina 27602 Mr. R. E. Jones, General Counsel Mr. Robert P. Gruber Carolina Power & Light Company Executive Director P. O. Box 1551 Public Staff - NCUC Raleigh, North Carolina 27602 P. O. Box 29520 Raleigh, North Carolina 27626-0520 Ms. Grace Beasley Board of Commissioners P. O. Box 249 Bolivia, North Carolina 28422 Resident Inspector U. S. Nuclear Regulatory Commission Star Route 1 P. O. Box 208 Southport, North C..rolina 28461 a
Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Mr. Dayne H. Brown, Chief Radiation Protection Branch Division of Facility Services N. C. Department of Human Resources 701 Barbour Drive Raleigh, North Carolina 27603-2008 Mr. J. L. Harness Plant General Manager Brunswick Steam Electric Plant P. O. Box 10429 Southport, North Carolina 28461 i
Enclosure REQUEST FOR ADDITIONAL INFORMATION FOR THE BRUNSWICKPRESSURE-TEMPERATUREAMENDMENTREQUEST The staff reviewed the reactor cavity dosimetry and fluence estimate aspects in CP&L's submittals of October 26, 1988 and March 30, 1989, including the Westinghouse report WCAP-10903, December 1986, " Reactor Cavity Neutron Dosimetry Program for Brunswick Unit 2."
Inasmuch as this report is the "first of a kind" associated with an amendment request, the staff would like some further discussion regarding reactor cavity neutron dosimetry and in particular the method of measurement extrapolation to the inside surface of the pressure vessel 0 d the justification of the fluence uncertainty.
In particular we will appreciate discussion of the following questions:
1.
Is there any benchmarking of the solid state track recorders used for fluence measurement?
2.
There was no discussion of neutron streaming in the cavity. How was it established that the measured values were not affected by neutron streaming or other cavity effects?
3.
There was no discussion how the void affected the neutron source (neutron leakage) which was taken into account in the calculation of the middle-plain two dimensional neutron transport. Such leakage is axially a symmetric.
4.
The outer assembly power (source) distribution was defined on an assembly by assembly basis. This method is known (from PWR analyses) to yield non-conservative results by about 10-15 percent which is the level of the indicated uncertainty.
Is there any justification for this practice?
5.
In the two-dimensional analyses the nominal (rather than the as-built) design dimensions were used. Given the high sensitivity of this calculation to the amount of water between source and detector, why was this factor ignored in the assessment c: the uncertainty?
I l
I J
I
-6.
Staff estimates indicate that BWR peripheral asseinbly power calculations have.significantly higher uncertainty than the inner assemblies. Why was this effect ignored?
7.
Toward the end of cycle the upper part of the core may experience significant plutonium burning, thus, affecting the neutrons / fission ratio as well as the neutron spectrum hardness. Was this factor accounted for?
8.
Beyond the calculated slope of the neutron flux through the pressure vessel, were any other cavity effects teken into account in the extrapolation?
9.
An uncertainty of 5-7 percent is estimated for the projection of the neutron flux within the pressure vessel. This is said to be based on the I
PCA benchmark. However, the kind of cavity and the extraneous materials present could affect the extrapolation. Has the similarity of Brunswick-PCA cavity been established?
- 10. The PCA was an order of magnitude more compact arrangement than the Brunswick reactor.
How does this affect the applicability of the PCA benchmarking?
_