IR 05000271/1993025

Insp Rept 50-271/93-25 on 931004-08.No Safety Concerns or Violations Noted.Major Areas Inspected:Radioactive Gaseous & Liquid Effluent Control Programs

ML20059F785
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	10/20/1993
From:	Bores R, Jang J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20059F778	List: IR 05000271/1993025 ML20059F775
References
50-271-93-25, NUDOCS 9311050080
Download: ML20059F785 (10)

Text

_ _ _ . ._ _ .

.

U.S. NUCLEAR REGULATORY COMMISSION

REGION I

Report No. 50-271/93-25 Docket No. ,50-271 ( License No. DPR-28 i l

Licensee: Yermont Yankee Nuclear Power Comomtion

,

RD 5. Box 169

}Lrattleboro. Vermont 05301 i Facility Name: Vennont Yankee Nuclear Power Station

!

Inspection At: Vernon. Vennont Inspection Conducted: October 4-8.1993

Inspector: ~ 'f /0 0 7 NJ.C. Jang, Sr. Radiation s[)ecialist Da'te /

Effluents Radiation Pmtection Section (ERPS), Facilities Radiological Safety and Safeguards Branch (FRS&SB)

Approved by: fy m /0 R.'J. BideQhief, EIfS, FRS&SB, Date Division of Radiation Safety and Safeguards Areas Inspgcitxi; Announced safety inspection of the radioactive gaseous and liquid effluent control progmms: including management controls, audits, calibrations of efuuent/ process radiation monitoring systems, surveillance and test results of air cleaning systems, and implementation of the above programs and the Offsite Dose Calculation Manual.

!- Resulls; Within the areas inspected, the licensee was implementing the above routine programs effectively. The responsible individuals in the Chemistry Depanment were I knowledgeable and well qualified to implement the above programs. No safety concerns or

'

violations of NRC requirements were identified.

I 9311050080 931029 PDR ADOCK 05000271'

G PDR

.

.

_ _ _ - _ - _ _ - _ _ _ _ _ _ _ _ - _ _ _ _ _ - - _ _ _ _

- . . - , . . _ .

,

.

!

'

.

.

DETAILS

, Individuals Contacted Licensee Personnel

. ,

R. Gaippardi, QA Supervisor

J. Geyster, Plant Health Physicist

• J. Herron, Technical Services Superintendent

E. Lindawood, Radiation Protection Manager

S. McAvoy, Chemistry Assistant

"

M. Morgan, Radiation Protection Assistant

S. Skibniowsky, Chemistry Manager M. Watson, I&C Manager . NRC  ;

• "

P. Harris, Resident Inspector

Denotes those present at the exit interview on October 8,199 Other licensee employees were contacted and interviewed during this inspectio .0 - Pumose The purpose of this inspection was to review the licensee's program in the following area (1) The licensee's ability to control and quantify effluent radioactive liquids,

. gases, and particulate i (2) The licensee's ability to calculate projected doses to the public from radioactive liquid and gaseous effluent releases during normal operatio .0 Previously Identified Item (Closed) Unresolved Item (50-271/93-11-01) Quantify the total amount of release for I-133 at the main stack sampling station during the containment purge operation. - The amount ofI-133 released should be used for the dose calculatio The inspector reviewed the licensee's investigation results, including corrective actions and discussed with the licensee the quantification and dose assessment  ;

techniques. The investigation results were very good and satisfied the requirements of the effluent control program. This item is close ,

4

'i

. . . -

. . - - .

.

.

..

4.0 Management Controls  : Organization / Program Changes The inspector reviewed the Vennont Yankee site organization chart and discussed with the licensee any changes made since the last inspection of this

'

area conducted in July 1992. The inspector determined that the effluent -

control program did not change since the last inspection. The Chemistry >

Department had the responsibility to implement the effluent control progra ' Review of Semiannual Renons The inspector reviewed the Semiannual Radioactive Effluent Reports for 1992 and the first half of 1993. The semiannual effluent reports provided the total radioactivity released in liquid and gaseous effluent The inspector also reviewed available second half of 1993 effluent release record .

The semiannual effluent report for the second half of 1992 not only provided a the total radioactivity released but also provided the calculated projected radiation dose to the public as require The inspector detennined that these semiannual reports contained no obvious anomalous measurements or omissions. The projected radiation doses to the total body and organs of members of the public were well below regulatory limits specified in the licensee's Technical Specifications. The inspector haa no further questions in this are .3 OA Audit 7

,

The inspector reviewed the QA audit (Audit No. VY-93 02) of the radioactive Effluent Control Program with respect to Technical Specification requirement This audit was conducted by the Quality Assurance Audit Group and technical specialists. The audit appeared to be a broad assessment of the program but lacked technical depth. Audit members identified four findings and five observations. Responses were timely and corrective actions were appropriat ;

'

The inspector noted that the findings and observations were not safety significant issues. The audit was minimally acceptabl *

,

5.0 Radiological Effluent Control Programs

' Radioactive Liquid Effluent Control Program The inspector reviewed Procedure OP 2610, Liquid Waste Disposal and

.

.

selected radioactive liquid effluent release pennits as part of the examination of the implementation of Technical Specification requirements for liquid effluent control During discussions with the licensee regarding the radioactive liquid effluent control practices at the site, the inspector noted that the licensee processed and recycled the liquid mdwaste. There were no radioactive liquid releases during -

1993 as a result of this progmm and therefore, no radioactive liquid release pennits were issued. The licensee's goal was to minimize routine release of ,

radioactive liquid from the site during nonnal operatio On June 28,1993, the licensee learned that the water sample collected at the South Stonn Drain was slightly contaminated with tritium at levels above the minimum detection capabilities of the contractor laboratory (Yankee Atomic Enviromnental laboratory). The licensee launched an extensive investigation, including soil and water samples from almost all manholes on site. All samples were analyzed (water for tritium and soil for gamma emitters) by the contractor laboratory. The inspector reviewed all analytical results for soil and water samples. Soil samples were slightly contaminated by Mn-54, Co-60, Cs-134, Cs-137, and Zn-65. Based on the analytical results, the licensee took immediate and long mnge corrective actions. The immediate corrective action included the cleanup of contaminated manholes. The long range corrective actions included the periodic cleanup of manholes, source identification of contaminants, and a dose contribution study. The inspector reviewed the investigation results and conclusions. Based on the reviews, the inspector concluded that the investigation was thorough and the conclusions were excellen Based on the review of the above procedure and discussions, the inspector determined that the licensee implemented the radioactive liquid effluent control programs effectively. No violations were identifie .2 Radioactive Gaspous EEluent Control Program The inspector reviewed the licensee's gaseous effluent control procedures and pennits to detennine the adequacy of implementation of the Technical Specifications and of the Offsite Dose Calculation Manual (ODCM).

Through review of permits, the associated procedures, and discussions with the licensee regarding radioactive gaseous effluent controls, the inspector detennined that the licensee met Technical Specification requirement ;

, _ _ _ _ . _ _ . . . - _ -

.

4 7 Dose Assessment Caoability During this inspection, the inspector reviewed the Offsite Dose Calculation '

Manual (ODCM) including use of site specific panuneters and current methodology for the noble gas, liquid, and particulates (including tritium and iodines) release pathways. The inspector found that the ODCM contained two dose calculation methods, Method I and Method I ,

Mgthod I:

$

Method I is a generally accepted simplified method to compute the projected dose to the public prior to release of radioactive liquids, gases, and particulates. Methcd I provides for conservative control of the effluent releases and was being used by the Chemistry Department at the sit ;

Method II:

Method II is an in-depth method to compute the detailed doses to the publi Method II is being used by the Nuclear Services Division, Yankee Atomic Electric Company, Bolton, Massachusetts for the Semiannual Repor During an inspection at the Maine Yankee facility in June 1993, the inspector perfonned an independent verification of the licensee's (Maine Yankee's)

capability for calculating projected doses to the public resulting from discharges of radioactive liquids and gases to the environment using both methods, Method I and Method II. The inspector used site specific parameters (e.g., dilution factor, total amount of radioactivity released, meteorological '

data, etc.) to calculate the maximum projected doses to the public using the

"PCDOSE" computer code. The results were compared with those obtained by the license The PCDOSE code was developed by Idaho National Engineering Laboratory (EG&G Idaho, Inc.) for the U.S. Nuclear Regulatory Commission. The code was designed to calculate the maximum projected radiation dose to an individual and the average dose to the population due to radionuclides in radioactive liquid and airborne effluent releases from a nuclear power plan The code was designed for nonnal operation rather than for emergency situations. The code was developed from the methodology found in both NUREG-0133 and Regulatory Guide 1.109 (Revision 1). The PCDOSE code serves as a basis of comparison with similar prognuns conducted by individual ,

utilities which operate nuclear power plant Comparisons of projected dose calculations perfonned using M:thod II at Maine Yankee and PCDOSE code results were in agreement. The inspector

'

_

. - ... _

_ , . . - . - . .-.

5 noted that Vennont Yankee is using the same computer code as Maine Yankee by contracting through the Nuclear Services Division, Yankee Atomic Electric Company, Bolton, Massachusetts. - The inspector, therefore, determined that . <

Vermont Yankee would have same capability as Maine Yanke The inspector also reviewed the results obtained using Method I and found them acceptable. The inspector determined that the licensee has the capability to calculate projected doses to the public. The inspector had no further questions in this are .4 Contamination of West Cooling Tower Bain Silt Recently, the licensee found that the silt in the west cooling tower basin was contaminated by Cs-137 and Co-60. During this inspection, the inspector toured the west cooling tower basin and reviewed the cleanup activitie About 200 cubic yards of sitt have been sluiced out of the cooling tower basin to the settling pond for dewatering. The licensee sampled and analyzed 18 samples, two samples per each deep bay (about 12 feet deep) of the cooling tower. The inspector reviewed available analytical results (14 samples) during this inspectio The activity of Cs-137 in all silt samples was lower than fallout background (around 1 pCi/ gram of soil). Co-60, however, should not be detected if the ;

contamination was due to fallout. The highest Co-60 activity in the silt samples was 10.9 pCi/ gram of silt, indicating plant related contaminatio Five silt samples showed the minimum detection activity of Co-6 The inspector reviewed the licensee's actions for the cleanup and stabilization of the silt during this inspection. After all of the silt has been collected and piled, then the pile of silt will be covered and secured with a heavy gauge plastic sheet to avoid any runoff. The licensee intends to apply to the NRC for permission to dispose of the silt on site in accordance with 10 CFR 20.30 During the discussion with the Chemistry Depanment staff members, the inspector noted that the responsible individuals had excellent knowledge in the areas of: (1) radioactive liquid and gaseous effluent controls, (2)

efnuent/ process Radiation Monitoring Systems (RMS), (3) quantifying the total e amount of liquid and gaseous effluent release using the RMS, (4) weaknesses of the current RMS, (5) protection of the public health and safety and the environment, and (6) ODCM requirement Based on the reviews of analytical results, interviews, and actions, the i inspector determined that the licensee handled this event very wel l l

!

!

. - .-- . _ _ - - - .

_ . _ _ _ _ ____ _ _ __

~. : l

.  :

,

I

"

6 Modification of Turbine Buildine Vents 1 Background The licensee established the turbine building roof vents release pathway and initiated a program to quantify the total amount of radioactive materials (iodines, particulates, and tritium) released through this pathway as of October 1,1991. The licensee calculated projected doses to the public using their

.

ODCM methodology. The licensee reported these results in the Semiannual-Report, the second half of 1991, as required. It should be noted that all ,

projected doses to the public were within the regulatory limit ,

During the previous inspection conducted in July 1992, the inspector noted that i

the licensee completed the preliminary engineering evaluation and decided to

'

reroute the turbine building roof vents to discharge through the plant main stack. This was to be accomplished during the next refueling outage (then scheduled for about October 1993). Therefore, the licensee decided not to

install a radiation monitoring system (RMS) on the turbine building roof vent The main stack RMS has the capability to monitor effluent for nonnal and emergency operations.

, C_itrrut Status of the Modification i During this inspection, the inspector reviewed selected documents and toured the turbine building to verify the modification results, as stated in the licensce's letter (BVY 93-96) dated September 10, 1993. The licensee's .

schedule, as provided in this letter, indicated that the turbine building ventilation effluent reroute would be completed sometime after the current refueling outage. The inspector reviewed this commitment and found it

'

acceptable. Air flow tests for air leakage from the turbine building and the ,

main stack will be perfonned during operation. The licensee estimated that the main stack air flow will increase, from 150,000 cfm to 200,000 cfm, due to addition of the turbine building ventilation. The licensee also had a plan to measure air flow in the main stack in order to detennine the isokinetic sampling pump flow rat .3 Assessment Although the minimization of gaseous release points was an excellent commitment as described in the above sections, many of the following tests and observations must be conducted in order to establish a technically sound gaseous effluent control progra !

. - . -- .

.. .

.

'

,

(1) Measurements of air flow in the main stack to establish a new flow profile to allow selection of the position for the isokinetic probe for the particulates and iodines sampling statio (2) Examination of the current air flow measurement devices in the stack and in the control room to ensure that the air volume released is accurately quantifie ,

(3) Utilize a second charcoal sample at the main stack for iodine 133 (I-133) measurement when unusual operations are commencing (e.g.,

bypass of standby gas treatment system during containment purge and during high primary and secondary leaks). The second charcoal sample can be pulled out for I-133 measurement'at the licensee defined i collection time during the unusual operations. The first charcoal sample collects iodine for a week to meet the Technical Specification requiremen ,

Based on the review of documents (i.e., EDCR No.92-407 ECN1, Turbine Building Roof Ventilation Re-Route) and discussions with the licensees, the inspector detennined that the licensee had a good understanding of the above items. The inspector stated that the implementation of the above items will be reviewed during a subsequent inspectio .0 Calibration of Effluent / Process Radiation Monitoring Systems (RMS)

The inspector reviewed the most recent calibration results for the following effluent / process monitor o Liquid Radwaste Discharge Monitor o Service Water Discharge Monitor o Liquid Discharge Process Monitor o Main Steam Line Monitors o Reactor Building Closed Cooling Water Monitor o Main Stack Monitor, Normal Rimge Noble Gas o AOG Building Noble Gas Monitor .

The I&C Department had the responsibility to perfonn electronic calibrations for the 1 above RMS. The Chemistry and Radiation Protection Departments had the i responsibility to per(onn radiological calibrations. All reviewed calibrations were perfonned at the reiuired l frequencies and tesults were within the licensee's acceptance criteri During the previous inspection conducted in April 1991, the inspector identified that the licensee did not have acceptance criteria for the linearity test. However, all

. . .- -- - . -- .

_ . __ _ _ -

- _ _ - __ _ __

,

t

. .I l

results appeared to be linear. The inspector discussed with the licensee a statistical method (e.g., linear regression method) to detennine the linearity. During this inspection, the inspector discussed with the licensee a linear regression method to calculate the conversion factor and the linearity. The licensee stated that the method will be evaluated, and possibly incorporated in the near futur During the review of radiological calibration results for the main stack nonnal range RMS, the inspector was infonned that the measurement results (countshninute) were obtained in the control room on a 6-decade logarithmic scale panel. The inspector discussed with the licensee that using the crude device in the control room for the calibration would introduce a very high reading error. Therefore, it would be very l difficult to obtain an accurate conversion factor and detennine linearity. The licensee i stated that the 6-decade scale will be replaced with a digital readout in the control room in the near future to improve the accumcy of the result !

!

'

Based on the above reviews, the inspector detennined that the licensee had an effective calibration prognun for the effluent / process monitors. No violations were identifie .0 Air Cleaning Systems ,

The inspector reviewed the licensee's most recent surveillance results as part of the i

'

examination of the implementation of the Technical Specification requirements for the '

Standby Gas Treatment Syste o Visual Inspections o In-Place HEPA Leak Tests o In-Place Charcoal Leak Tests o System Air Flow Tests o Delta Pressure Tests l o Labomtory Tests for the Iodine Collection Efficiencies i i

l

'

All reviewed test results were found to be within the licensee's acceptance criteri The inspector also noted that the responsible individual had a good knowledge of the i operational requirements for the air cleaning systems. The inspector reviewed i pressure drop test results for the AOG and Radwaste Buildings and noted that the test l results were within the licensee's acceptance criten !

!

Based on the above reviews, the inspector detennined that the licensee impicmented l the requirements for the above system effectively. No violations were identified m ;

this are I i

l i

l

"

l l

l

!

!

,. , . . - _ . . _ -_

.. . . . . .-. . -- . . - - . . . -

.

.

.

.

9.0 Exit Interview The inspector met with the licensee representatives denoted in Section 1.1 of this inspection report at the conclusion of the inspection on October 8,1993 at the Vennont Yankee site. The inspector summarized the purpose, scope, and findings of ;

the inspection The licensee acknowledged the inspection finding .

t

>

'

t i

>

l

.l

i  !

,

i

, . . . . . - .. .,. . - _ ____--_______ _ - _ _ _l