05000336/LER-1983-010, Forwards LER 83-010/03L-0.Detailed Event Analysis Encl

Forwards LER 83-010/03L-0.Detailed Event Analysis Encl

ML20072V310
Person / Time
Site:	Millstone
Issue date:	03/31/1983
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20072V315	List: 05000336/LER-1983-010, Forwards LER 83-010/03L-0.Detailed Event Analysis Encl
References
MP-4847, NUDOCS 8304110555
Download: ML20072V310 (2)

LER-1983-010, Forwards LER 83-010/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3361983010R00 - NRC Website

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March 31, 1983 MP-4847 Mr. Ronald C. Haynes Regional Administrator, Region 1 U. S. Nuclear Regulatory Commission Regional Office 631 Park Avenue King of Prussia, Pennsylvania 19406

Reference:

Facility Operating License No. DPR-65 Docket No. 50-336 Reportable Occurrence R0 50-336/83-10/03L-0

Dear Mr. Haynes:

This letter forwards the Licensee Event Report 83-10/03L-0 required to be submitted within thirty days pursuant to Millstone Unit 2 Appendix A Technical Specifications, Section 6.9.1.9.b conditions leading to operation in a degraded mode permitted by a limiting condition.

An additional three copies of the report are enclosed.

Yours truly, NORTHEAST NUCLEAR ENERGY COMPANY

/

2W E. J. Mroczka Station Superintendent Millstone Ncclear Power Station EJM/RB:jlc

Attachment:

LER R0 50-336/83-10/03L-0 cc:

Director, Office of Inspection and Enforcement, Washington, D. C. (30)

Director, Office of Management Information and Program Control, Washington, D. C. (3)

U. S. Nuclear Regulatory Commission, c/o Document Management Branch, Washington, D. C. 20555 7

h4110555930331

/

g ADOCK 05000336 f'.

PDR

i ATTACHMENT TO LER 83-10/03L-0 NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION - UNIT 2 FACILITY OPERATING LICENSE NbMBER DPR-65 DOCKET NO. 50-336 Cause Description and Corrective Actions During plant cooldown on 2 March 1983, the pressurizer spray water temperature

. differential exceeded the limit outlined in T.S. 3.4.9.2.c, a maximum pressurizer spray water temperature differential of 350 F.

This occurred while in Mode 4, with an RCS temperature of approximately 290 F, a steam space temperature of approximately 545 F and with RCS pressure less than 500 psig.

At this RCS temoerature, with only one RCP operating, there was insufficient pressurizer pressure control, such that when auxiliary spray was initiated, spray water temperature differentials of 367 F for a period of approximately 8 minutes and 391 F for a period of approximately 4 minutes occurred.

An engineering evaluation was performed on the pressurizer spray nozzle and the pressurizer spray piping to determine the effects of the out-of-limit condition on the fracture toughness properties of the pressurizer.

It was determined that these transients did not compromise the structural integrity of the pressurizer spray nozzle or the pressurizer spray piping, and that the pressurizer remains acceptable for continued operation.

A Technical Specification change is currently being internally reviewed.

This would allow a greater pressurizer level span, which would help to increase the actual pressurizer cooldown while in Mode 3.