ML20058E766
| ML20058E766 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 10/30/1990 |
| From: | Loflin L CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLS-90-224, TAC-76068, NUDOCS 9011070320 | |
| Download: ML20058E766 (2) | |
Text
-
1 Cp&L
_ Caronna Power & Ught Company
. SERIAL: NLS-90 224
-)
OCT 3 0 1990 United States' Nuclear Regulatory Commission j
ATTENTION: ; Document' Control Desk Washington, DC 20555 1
i BRUNSWICK STEAM ELECTRIC PLANT UNIT 2 i
' DOCK'T NO. 50 324/ LICE.;SE NO DPR-62 CORE SP2AY SPARCER INSPECTION RESULTS
='
.(NRC TAC NO~ 76068) f
- centlemen
)
.On September. 18, 1990,- Mr. N. B. Le of your staff requested that Carolina l
3 Power & Light Company (CP&L) provide additional information regarding the.
Brunswick Steam. Electric. Plant,' Unit 2' inspection report dated February 23, 1990 for-the core spray spargers.
Subsequently, on October 17, 1990, CP&L proposed a verbal response to the NRC-request but was requested to provide a
' written response.
4 The following is CP&L's response-to the three requests of 1
f September 18, 1990 - To facilitate the understanding of CP&L's response, the
. NRC request precedes each CP&L response.
{
. NRC Request 1:
. CP&L's. plans for future repair of the subject crack or replacement of related piping.
I d
Response
It is CP&L's intent, pending identification of a suitable i
repair, to repair the core spray pipe crack in the next L
Unit 2 RF0 (currently scheduled'for. September 1991) CP&L's plan for repair, could entail'the use of a clamping device l
around the crack, welding of the crack or other technically acceptable options.
NRC Request 2:
CP&L to address the potential consequences in the reactor vessel from small loose pieces of the-subject crack pipe as referred to in Reference 2 of the CP&L February 23, 1990 report.
Response
This concern was addressed in Section 4.4.2.2 of the report provided in our March 31, 1988 submittal which concluded that there were no. safety concerns posed by any postulated loose parts. Our February 23, 1990 report determined in
]
Section 2.1.3 that the initial report remains bounding.
t /
Alt Fayetteville Street
- P. O. Box 1551
- Aateigh. N C 27602 RW -
v.4MfeUJfab?fMWudFtKCHAMWJEW#
fgg/
(
9011070320 901030 if ADOCKOSOOyja
//p J
PDR Q.
- Q% +
p;
'J3 s a
O,
!v 4
,[ [,
Serial:
NLS-90-224 NRC Request 3:
Further CP&L analyses are nee.ded to ensure that the crack will not propagate with a faster rate such that it will affect the safe operation of the plant.
If the growth rate is found to be faster than that postulated in the CP&L February 23, 1990 report, a justification for contiaued operation must be provided to the staff.
Response
The concern appears to center around an accelerated rate of crack propagation versus the range of crack propagation. As evaluated in the March 31, 1988 and February 23, 1990 report, the crack growth is expected to arrest as it approaches 180*.
Section 3.2.3 of the March report and Section 2.1.2 of the February report conclude that a crack up to 235' can be tolerated without gross pipe failure.
Given that the crack arrest is evaluated to occur prior to achieving gross failure, the rate of acceleration of the crack should not be a conce rn.
=
We hope that the above additional information will enable the staff to complete its review of our February 23, 1990 report.
Pl';ase refer any
=
questions you may have regarding this submittal to Mr. M R. Oates at (919) 546-6063.
8 Yours very truly, L. I. Lof n Manag Nuclear Licen ng Section DBB/cwh (858BNP) cc:
Mr. S. D. Ebneter Mr. N. B. Le Mr. R. L. Prevatte m
a N
l mq
"-