United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Sampling Drywell Atmosphere Before a Release

HPPOS-170 PDR-9111220188

Title: Sampling Drywell Atmosphere Before a Release

See the memorandum from L. J. Cunningham to R. B. Samworth

dated November 3, 1988. Sampling drywell atmosphere is

required before each and every purging or venting.

Furthermore, methodology and parameters in TS referencing

the ODCM, should accurately represent the contents of the


Region V requested assistance in interpretation of two

current Washington Nuclear Plant - Unit 2 (WNP-2) Technical

Specifications (TS): TS 3/, and TS 3/

Specifically, Region V asked: "Does TS Section 4.11.21 and

Table 4.11.2 require a sample of drywell atmosphere be

taken and analyzed prior to each vent and/or purge

operation through the Standby Gas Treatment (SGT) system?"

Region V also asked: "If prior-to-release samples are

required, should this be reflected in the ODCM, along with

an appropriate decontamination factor to account for SGT


NRR reviewed the Inspection Report documenting the

positions of both the inspector and the licensee in regard

to the subject question. NRR agreed with the position

expressed by the licensee's Corporate Nuclear Safety Review

Board (CNSRB) member at the November 27, 1985 meeting of

their Plant Operations Committee (POC) recorded on pages 10

and 11 of the Inspection Report. WPN-2 TS with

its Table 4.11.2 requires that a grab sample be taken prior

to each purge and vent from primary containment. TS provides additional requirements for the case of

purging or venting through other than the SGTS, but says

nothing about when the SGTS is used. The applicability of

TS 3/ is "At all times." Therefore, the answer to

the first question of Region V is "yes."

In regard to the second question, TS 3/ ties the

sampling and analysis program of Table 4.11.2 to dose rate

determinations "in accordance with the methodology and

parameters in the ODCM." Thus, statements regarding these

determinations should be incorporated in the ODCM.

Regulatory references: Technical Specifications

Subject codes: 7.3

Applicability: Reactors (BWR)

Page Last Reviewed/Updated Thursday, March 29, 2012