GNRO-2017/00058, Special Report Regarding Gaseous Radwaste Treatment System Out of Service

Special Report Regarding Gaseous Radwaste Treatment System Out of Service

ML17261B268
Person / Time
Site:	Grand Gulf
Issue date:	09/14/2017
From:	Giacini M Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2017/00058
Download: ML17261B268 (5)

Text

-Entergy Entergy Operations, Inc.

P.O. Box 756 Port Gibson, MS 39150 Mark Giacini General Manager, Plant Operations Grand Gulf Nuclear Station Tel. (601) 437-2129 GNRO-2017/00058 September 14, 2017 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Special Report - Gaseous Radwaste Treatment System Out of Service Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29

Dear Sir or Madam:

\

This Special Report is submitted in accordance with Grand Gulf Nuclear Station (GGNS) Unit 1 Offsite Dose Calculation Manual (ODCM) Specification 6.11.7 Action B.1 due to non-functionality of the gaseous radwaste treatment system.

This report contains no new regulatory commitments.

If you have any questions or require additional information, please contact Douglas Neve at (601) 437-2103.

MG/dre

GNRO-2017/00058)

Page 2 of 2 cc: U.S. Nuclear Regulatory Commission ATTN: Mr. Siva Lingam, NRR/DORL (w/2)

Mail Stop OWFN 8 B1 11555 Rockville Pike Rockville, MD 20852-2738 U.S. Nuclear Regulatory Commission ATTN: Mr. Scott Morris (w/2)

Acting - Regional Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150

Attachment 1 to GNRO-2017/00058 Special Report on Gaseo'us Radwaste System Non-Functional GNRO-2017/00058 Special Report on Gaseous Radwaste System Non-Functional Due to Offsite Dose Calculation Manual (ODCM) LCD 6.11.7 The following events occurred requiring the submittal of this report:

• On 8/12/2017 at 0700 hours0.0081 days <br />0.194 hours <br />0.00116 weeks <br />2.6635e-4 months <br />, the gaseous radwaste treatment system was declared non-functional for dOCM Limiting Condition for Operation (LCO) 6.11.7.A not met.

• On 8/19/2017 at 0657 hours0.0076 days <br />0.183 hours <br />0.00109 weeks <br />2.499885e-4 months <br />, after attempts to restore the system to functionality, and the system was not being restored ~o functionality within 7 days, Grand Gulf Nuclear Station (GGNS) declared ODCM Specification LCO 6.11.7.B not met, which requires this Special Report to be submitted with 30 days.

Per theGGNS ODCM Bases 6.11.7, the following information is to be provided in this Special Report:

1) An explanation of why the gaseous radwaste was being discharged without treatment

Response

The gaseous radwaste discharge was being treated, but at less than optimal efficiency because of a failed part of the treatment system that raised the temperature of the treatment s:ystem.

The gaseous release from GGNS has been and continues to be well below ODCM limits..

2) Identification, of the non-functional equipment or subsystems which resulted in gaseous radwaste being discharged without treatment

Response

The non-functional equipment which resulted in the gaseous discharge was the GGNS Unit 1 Offgas Charcoal Vault Refrigeration System. Specifically, the refrigeration system defrost h~ters were not functioning.

3) The reason for the non-fun~~tionality

Response

The GGNS ODCM states that the system controls must be in the "treat" position, and the system valve lineup must not be in the "bypass" position to be considered as functioning. The system was maintained in the functioning GNRO-2017/00058 configuration at pll times.

The GGNS Updated Final Safety Analysis Report (UFSAR) states that the charcoal absorber bed normally operates at approximately 0 degrees Fahrenheit.

GGNS considered that the system, was non-functional because the system was not performing as stated in \tfle Updated Final Safety Analysis Report (UFSAR).

4) The action(s) taken to restore the nonfunctional equipment to FUNCTIONAL status

Response

Grand Gulf Nuclear Station is repairing the Offgas Charcoal Vault Refrigeration System to ensure that the charcoal absorber temperature remains within design limits by restoring the refrigeration system heater.

5) Summary descriptions of the action(s) taken to prevent recurrence

Response

Repairs to the system are in progress.

Grand Gulf Nuclear Station will continue to repair; and will operate and monitor the system in accordance with system operating procedures, the system design, and the unit ODCM.