B14321, Forwards Nonproprietary WCAP-13520, Reactor Cavity Neutron Measurement Program for Cyap,Haddam Neck Plant. Rept Documents Testing & Analysis of First Set of ex-vessel Dosimetry Removed from Reactor Vessel Cavity

Forwards Nonproprietary WCAP-13520, Reactor Cavity Neutron Measurement Program for Cyap,Haddam Neck Plant. Rept Documents Testing & Analysis of First Set of ex-vessel Dosimetry Removed from Reactor Vessel Cavity

ML20127N503
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	01/15/1993
From:	Opeka J CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20127N507	List: B14321, Forwards Nonproprietary WCAP-13520, Reactor Cavity Neutron Measurement Program for Cyap,Haddam Neck Plant. Rept Documents Testing & Analysis of First Set of ex-vessel Dosimetry Removed from Reactor Vessel Cavity ML20127N513
References
B14321, NUDOCS 9301290216
Download: ML20127N503 (2)

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L L J CZZU,C.[ (203) 665-5000-I January 15, 1993 Docket No. 50-213 B14321 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:

Haddam Neck Plant Ex-Vessel Dosimetry Procram In a letter dated October 1,1991,'" Connecticut Yankee Atomic Power Company (CYAPCO) forwarded to the NRC Staff a description of the reactor Ex-Vessel Dosimetry Program that had been implemented as part of an Integrated Surveillance Program for the Haddam Neck Plant. In a letter dated May 19, 1992,i2' the NRC Staff approved the Ex-Vessel Dosimetry Program for the Haddam Neck Plant.

The Ex-Vessel Dosimetry Program was initiated at the Haddam Neck Plant duri_ng the Cycle 15 refueling outage in conjunction with the removal of _the thermal shield. ' Prior to removal of the thermal shield, the neutron exposure of the reactor vessel was monitored by periodically removing surveillance capsules.

These surveillance capsules contained samples of the reactor vessel plate and weld materials and were attached to the thermal shield. With the removal of -

the thermal shield, a capsule containing Haddam Neck Plant vessel materials was'placed in the Millstone Unit No. 3 reactor vessel to continue irradiation of the specimens. This capsule, along with the ex-vessel oosimetry placed in the Haddam Neck Plant reactor vessel cavity, forms _ the integrated surveillance program for the reactor vessel.

The Integrated Surveillance Program allows the Haddam Neck Plant to continue to operate in compliance with the requirements of 10CFR50, Appendix H.

The first set of ex-vessel dosimetry was removed for analysis during the Cycle 16 refueling outage and new dosimetry was installed in its place.

(1) E. J. Mroczka letter to the U.S. Nuclear Regulatory Commission, "Haddam -

Neck Plant, Reactor Ex-Vessel Dosimetry Program," dated October 1,1991.

(2) A. B. Wang letter to J. F. Opeka, "Haddam Neck Plant Ex-Vessel Dosimetry Program (TAC No. M83010)," dated May 19, 1992.

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- U.S. Nuclear' Regulatory Commission B14321/Page 2

' January 15, 1993 The purpose of this letter is tu provide the NRC Staff with two copies of the-Westinghouse Report WCAP-13520, " Reactor Cavity Neutron Measurement Program :

for Connecticut Yankee Atomic Power Company Haddam Neck Plant."

The Westinghouse Report, Attachment No.1, documents the testing and analysis of the first set of ex-vessel dosimetry removed - from _the reactor vessel cavity. The activity of the various materials in the dosimetry was determined and neutron transport calculations were performed to determine the current neutron exposure of the reactor vessel. The maximum fluence for the_ belt-line region at 17.5 effective full-power years (EFPY) was determined to be-4.01E+19 n/cm2 (Energy > 1.0 MeV), Based on these -results, the highest projected fluence for the belt-line region at 32 EFPY-is 9.82E+19 n/cm2 (Energy > 1.0 _

MeV).

We believe that the information contained in this letter is evidence of-CYAPCO's continuing effort to assure reactor vessel integrity and safety for its remaining life.

We remain available to answer any questions you may have.

Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY bAl' v J. F. Opak4 U Executive Vice President cc: T. T. Martin, Region I Administrator A. B.-Wang, NRC Project Manager, Haddam Neck Plant-W. J. Raymand, Senior Resident Inspector, Haddam Neck Plant 1

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